Often (I don't claim always), such a person is not as good at being an engineering manager as someone who was just ok with developing, because they keep wanting

Often (I don't claim always), such a person is not as good at being an engineering manager as someone who was just ok with developing, because they keep wanting to interfere in low-level development decisions. Because, you know, those were the kinds of decisions they made when they were doing the job they actually loved doing.