I think describing the choice of implementing a random tech tree as "stupid" is a bit harsh. Stellaris and Olde World also have a similar random tech tree system.
Your incorrect to say that in the newly proposed system research cost will be doubled. What Brad said was (and I'm paraphrasing here) is that you will get the linear non random options at the normal cost but you will also get some random options that will have a discounted cost (basically some researcher had a eureka moment and made an amazing breakthrough in one field). I think this is actually a good compromise.
Both linear and random tech trees have pros and cons and it comes down to personnel preference. However calling random tech trees stupid and berating the devs for making that choice is not constructive.