> advantage of original founders who remained extremely engaged
I'm skeptical about whether this is true in a straightforward way.
For one thing, most of the complaining about the (relative) decline in engineer-centric culture at Google has happened since, oh, about six months after Larry returned to the CEO position. More wood behind fewer arrows, big push on G+, more shutdowns, more constraints on 20% time, etc. (... although I have no personal experience of Google under Schmidt)
For another thing, if Sergey is engaged in anything other than his (awesome!) blue-sky projects in X, he puts a lot of work into hiding it. Seriously. Don't get me wrong, I'm willing to give him a thumbs-up, if he's going to keep putting his capital (financial, social, and political) into socially transformative projects. But I would not describe him as engaged with basically anything web-related (search, ads, social, android, etc).
Also, you seem a little confused about X. X is a tiny fraction of engineers, and as such it's not clear what it has to do with "bringing in top engineers". I mean, unless you mean "bringing in top engineers and preventing them from working on money-making projects". And also, btw, it's mostly within the Mountain View office complex.
This post probably gives the wrong impression. I'm long GOOG, and I think X is awesome, and I think Google is still doing more good than harm. But I believe these in spite of the other stuff I mentioned here, not because of "original founders who remain extremely engaged", especially in the context of sergiosgc's comments.