Well, 50% of programmers are at most mediocre—or worse. And only maybe 1% of programmers is able to write significantly better code than all others.

So in result, just by the means of statistics, all code is necessarily crap. (Besides the extremely seldom pearls written by some independent geniuses).

Frankly this is unavoidable on an industrial scale of production, I guess. At least as long as we can't clone "10 x programmers".