merc, rok temu

might as well have a glowing resume from working on those products (resume-driven development).

This is so true. Getting promoted requires showing impact. If you use off-the-shelf tools (that happen to be easily maintainable) that’s not an impressive impact. If you invent a new language (and make up a convincing reason it was necessary) and so-on, that’s really impressive and you can get promoted. The minefield you leave behind that makes maintaining your solution so difficult is just another opportunity for someone else to get promoted.