> It's that the people making enterprise software have terrible taste and can't even see (I am convinced) that the thing they built is ugly and hard-to-use.

Generally the issue with enterprise is that its designed to appeal to the stakeholders who will make the purchasing decision, not the person who is actually going to use it. The people making it may have great taste and know damn well what they could do to make it more usable, but if a clean and easy tool doesn't match someone's preconceived notion of what the purchaser thinks the tool ought to look like then it's not going to fly.