Does a "fear" of experienced (or pro) players keep you from playing Sins online?
Yes, and no. I am a casual player, not a pro, and probably never will be. Between work and school. I average about an hour a day to play, maybe an extra hour working on an idea for a mod. That is it. So my chances of making a normal contribution (read "not a burden") to my team, are low. So im better off not playing team online play. Single online play against an ai, is probably much the same as single offline ai, and single human vs. human, is again constrained by either matching with a pro, that is disgusted by the lack of challenge, and my disgust at such poor performance, that yes, as many people have already said, the pro's stop because of lack of challenge, and the casual players stop because it gets depressing getting beat all the time.
Since i am not a pro, i dont know how to fix this. But as someone also pointed out earlier, with as many sales as Sins has had, which is alot, and the relative small size of online play, it seems a very strong indication that many of these people buying the game are indeed casual players, they play for the single player fun and experience. I for one as a casual player would appreciate efforts by the dev team to enhance that. Expansions with content, new features and craft, new diplomacy options and choices, new tech tree researches, a campaign or campaign editor would be very very much appreciated.
However just because im a casual player doesnt mean that i should disregard those players that enjoy online play and the challenge of other pro players. So a nice portion of dev time, and enhancements, to the online aspect of the game might, and hopefully will prove an interesting and helpful addtion for them.
It is my opinion, and a casual player at that, so perhaps i am totally misreading this, but since WOW dominates not only much of the game scene, but also much of the online scene as well, maybe there is something we can learn there, from our observations of what they do.
Do we need a certain kind of online presence? Or a certain size? How do we make it competitive and challenging for not only new players, but also the experienced ones? All of this means popularity, and money, and prestige in the gaming industry.
But what kind of game is WOW? vs. Sins? In WOW i run around and kill things, and make levels, and get into guilds, and bash monsters with friends, and travel to other countries, filled with snow, with snow monsters to bash, and swamps with swamp monsters to bash, and get another level, and get a new piece of armor, and get to put "Gallant" in front of my character name when i play. And pets, and special clothes or visible "shows" that i am accomplished.
Sins, however is Chess, it is not the checkers of fast bashing and leveling. There is diplomacy and research, and buildup of not only resources, but also fleets, while fending off either pirates or opponents. But there may be things we can still learn from WOW the checkers king.
What if there were levels beyond 10? And different lands? How can we make vocanic worlds and ice worlds more than a backdrop? Increase the temperature in the well, so that we have to watch how long we are in the well, or risk burning up? Or the reverse for the ice worlds? That we have to watch our dropping temperature that affects weapons performance in the well, and if we stay too long, ships risk being iced over and frozen, monuments of failure drifting in space? Is this a way to change some of the mechanics of the gravity well so it is different from planet to planet?
And magnetic storms, and plasma storms and wormholes and asteroid belts? How can we make these "different"?
Magnetics affects anti-matter, but sporadically, so instead of having a complete nullifying of abilities, we might make it sporadic and variable? An algorithm that calculates given weapon and ability percentages every 5 or 10 seconds and changes the values accordingly? Plasma storms may stop communication with anything outside the cloud, so that rescue in the cloud becomes something out of the question? No armada calls from inside the cloud? How do we make what we have more visible? Do ships change color as they enter a high magnetic field? Or grow red hot in the well of a volcanic world? The visibility of anything in the game only enhances it for the players. Battle scarred ships with laser burn marks half-way down the length of the ship? haha
It only makes the gaming experience better.
I wish we had new pieces of "armor" to decorate our ships with, and new colored plating, or different bridge structures or additional sections to add to the ship, an upgraded plasma engines to replace the old anti-matter ones? I wish i could put "Gallant" in front of my character name as a show of achievement. Or new or special items after defeating the Vasari at the 'Battle of Marzi' in the Outer Rim. They are just "show off" items really, but even in single player, with no one seeing it except me, those "shows" are evidence of my achievements, and pride in a game that i enjoy playing.
The achievements list could be "public", displayed when going on line, that gives players recognition with their peers.
And the showy "items" like different or new bridge structures, twin weapon mounted fins on craft, different colors for ships, extra guns, upgraded gauss cannons that "look" different from the entry level ones, gold piping around the edges of the structrures all add to that "reputation".
I wish we could have pets. An "Escort Jet Turret" that accompanies me on missions or "Sleek Torpedo Drones", or a "Targeting Satellite" drone that aids me if im Advent instead of Tec.
I could go on and on, but you get the idea. 
Anyway, with regards as to what to do about single player vs. online?
Casual players like myself, will probably go on playing single player, and the online players will attempt to go on with games online with friends or challenges with strangers for competition. I dont know how to fix multiplayer, but i have ideas, everyone has. Taking ideas from games like WOW may help us, or they may not. I'm not a gaming analyst, so i dont know, i am just guessing and making wishes as a player.
Sins is not WOW, but maybe we can learn from them, and try to copy some of what they do. But we will never be WOW, and at some point we have to ask ourselves, if we are Chess? Then what do we do to make Chess as interesting as Checkers for those quick, down and dirty, bash and level fans out there? And where do we draw the line?
Sins is not WOW. But if we know that going in, maybe we can avoid the mistake of copying too much.
Just some thoughts,
Take care,
-Teal