Plenty of early stage tech leads DO use wordpress and rails because their company doesn't need something more. You just don't hear about them often because they won't be sexy enough for HN. YAGNI.
OK so then does YAGNI apply to investment? Why not let existing firms handle it in the S&P?
> YAGNI (continued)
over-engineering is definitely a problem, but so is hindsight bias.
I think that most non-trivial tech builds involve some smart investments and some dumb ones. It's essentially a portfolio of decisions made in the face of uncertainty. YAGNI is cynicism and hindsight bias, and over-generalization.
I think this is less obvious than it should be because of the popularity of the highly cynical "agile" approaches that consider a project that does not plan beyond the next sprint as somehow not taking on code debt.
Yes, don't rebuild your own balanced portfolio or pay someone to "beat the market" for you; just buy a COTS ETF, put it in the server closet and forget about it for a decade.
This point is valid in the same way as telling a startup founder to give up the startup and invest in the S&P 500. It's trivially true, but ultimately useless advice.
Building technology is hard precisely because there are so many tradeoffs. Speed to market vs scalability is one of many. It's silly to pretend that there is some kind of rote obviousness to never caring about scale in the early stage, anymore than there is rote obviousness to just investing in the S&P.
Ex post, most startup founders/investors should have just invested in the S&P, and most early stage tech leads should have just used Wordpress or Rails.