I'm not a webdev, but still think it's shit. And I'm even old enough to know most of those Icons from the days in which they were considered modern. The whole interface is dated and with strange hacks. It's useful, but could be made better. But I think there are two different parts coming together here, namely UI and UX. The UI is old school and a bit ugly, while the UX is very basic and sometimes strange. And together they make a criticizable interface.

But actually, who cars? It's still doing its job well enough, while delivering a very powerful experience. On that level of ability, it's quite hard and demanding to build a good interface, and a dev who is so deep in CLI that he even builds his own terminal is unlikely to have the necessary competence in that area to make something better.