Very few people stood around doing literally nothing waiting for Houlon. There was other stuff to do, all the time - people announced houlon and everyone flocked. Heck, even the people who stood around doing nothing half the time ended up as targets for the flame item that lets you kill your own faction.
It’s extremely obvious if you played MoP that the people designing the content enjoyed designing the content, and that lead to good content, and people liked it. Sure, it was down on Wrath; no doubt. A lot of people whinged at the time. But by and by, it is remembered fondly. None of the mechanics SCREAMED time waste for the sake of wasting time. Everything was themed, everything told a story, it felt fun to be part of it. Not everyone enjoyed MoP, but not many people complained that it was badly made or clearly designed to waste time or anything like that. Most complaint was about disliking the theme - which, ultimately, is ok. Not everyone is on the same page in this regard - different people like different things.
The Maw doesn’t tell a story. It is bland. It is generic. Its inhabitants are dull and forgettable. Its mechanics are blatantly designed to take longer, rather than possibly well hidden design to do the same. It doesn’t FEEL like the people who made it enjoyed the process, it doesn’t FEEL like they want me to enjoy it. It doesn’t have a theme, a design, a goal. It just exists because it had to exist as a means to an end.
Whether or not this is the reality or not, this is the end result. Ultimately, even if they all hated their jobs and just did a good job of hiding it, the end result is the same; they did a good job. The Maw does the opposite; either they simply don’t care about their players having fun, or they did a very bad job at conveying it.
I didn’t particularly like Mechagon but it’s not in the same category as the maw. I probably didn’t like it because of the context it existed in; if it had existed as an extension of the Ulduar-style era tinkerer wing, say, I probably would have liked it. It at least has a story and follows through on it quite well. The Maw is just… a different animal entirely.