I am young in the Industry and I already see examples of such people. They go through a recursive cycle of "visible productivity" in terms of fancy features which break three months later. Then, they are on a "fire fight" trying to fix this "broken feature". The worst thing you could do is try to look at their code and attempt to reuse components for anything you want. I however don't completely blame such people, I think it is the nature of the startup world we are living in where the idea is to ship as fast as possible and technical debt be damned.