My own position is that "stuff" can be more interesting and more nuanced and more specific than "ah, just chuck some maneuvers on it."
SD can be a hammer, and when every potential new fighter subclass looks like a nail, there's little thought given to how this would look and work if you removed SD from the equation, or dramatically changed how they worked. There's no innovation, no new play experience, just the BM with a new coat of paint.
To be a Cavalier, I'd want to be more than "BM with some Mounted Combat-style fobs." To be a Scout, I'd want to be more than "BM with some skill-enhancing fobs." I already have a BM. More/different maneuvers are nice, but it doesn't change the experience of playing the character (especially in combat). I want mechanics that match the fiction, which means that playing a tactical master like the BM should feel different from playing a courageous cavalier or a mobile scout. In combat, I don't need to be making decisions about allocating resources, I need to be charging into melee or setting up an ambush. It shouldn't be a tactical decision (Do I charge into combat, or something else?), it should be just what I do ("I charge into combat. Stuff happens.").
There's plenty of room for mechanics beyond "at-will cantrips" without just giving up and saying "I dunno, change two or three things about the Battle Master, that's good enough."