It is the same reason "nobody ever got fired for buying IBM", namely its a variation of conventional wisdom (now). Which, perhaps, is also to say its a combina

It is the same reason "nobody ever got fired for buying IBM", namely its a variation of conventional wisdom (now). Which, perhaps, is also to say its a combination of factors: 1) Herd mentality (also known as 'social proof') 2) Porfolio theory (diversification of ideas, attention to details) 3) Network effects (iff younger teams, 2x rolodexes >1x) 4) Adverse selection (co-founder is a vetted hire; early hires are hard; and may imact outcome disproportionately). So not entirely irrational either.The question is: is it remdiable and is such remidiation cost-effective? Two considerations: must be so for <investors> as well as for <founders>. But yes, a heuristic being overly generalized, is it seems to be a variation now of cognitive bias.