Same experience. IMO the keyword here is "integrated". I'm showing my age here, but when game companies used to hire people to do tools, or leverage internal k

Same experience. IMO the keyword here is "integrated". I'm showing my age here, but when game companies used to hire people to do tools, or leverage internal knowledge, it was often things like MFC in Windows... or the ones you mention. They would often run outside the game, often displaying lo-fi graphics. The only "integrated" tool back in the day was a Quake-like console. But eventually people started demanding tools that were more integrated, and immediate GUI was in the right place at the right time.