I've been designing game APIs for 20+ years, actually. And that's what I'm doing now as a contractor.
I'm still working in C++ like I was in 1993 as well. I first learned C++ in 1989, so that's also 20+ years experience.
>all those years of experience could have, and often do, entrench very bad habits.
Working exclusively with languages like PHP, Ruby, and JavaScript can entrench some pretty atrocious habits as well. I would put my "started with assembly language and moved eventually to high level scripting languages" habits up against a "started with JavaScript" programmer's habits any day.
>Finally, the data suggests homogeneity is valuable in early startups.
What data? I think compatibility between developers is important. But I'm working on a project right now where the median developer age is about 25 (I'm more than twice as old as some team members), and I'm making crazy fast progress on my part of the project, keeping everyone happy. Beyond happy, really; no one expected me to get as far as I have this quickly. And yet I'm putting in 30 hours a week or so.
I think being awesome is valuable, on any project, startup or otherwise, and that "fundamental values and principles" is a red flag indicating "OK working tons of overtime", which is clearly not necessary if you have the awesome.