IMO yes and here is why:
Let's go back in time... many years ago... to 1E AD&D. You had the Player's Handbook, and later Unearthed Arcana and Oriental Adventures. Other than some settings books (like Dragonlance), for making your character concept and deciding your races, etc. that was pretty much it. Nearly all the additional books were meant to build on the rule systems for the game: Dungeon Master's Guide, Monster Manuals 1 and 2, the Fiend Folio, Deities & Demigods, The Manual of the Planes, The Wilderness Survival Guide, the Dungeoneer's Survival Guide, etc.; and thus revolved more around building the "game world" and the adventure. The
adventure is what was important. The excitement of the quest! Not what new feature your PC was about to get, or what other class you should take to maximize your damage potential or try to break the system.
Now, I blame 2E when the bloat came and starting this. Every race and class eventually had a guide book of one sort or another, there were so many new things with kits and such it was ridiculous in the end. I hope 5E never gets to this point, but it has a healthy start in that direction.
Don't get me wrong, there was plenty of stuff in AD&D that had its issues as well!
Now, we come forward to the present. Today I was discussing house-rules with one of my online players. He started mentioning a race I and some spells I never heard of! Later, he told me they were from Acquisitions Incorporated.
Sigh... When players want to play things that, as a DM, I have no access to and really don't want to add
more stuff to my games, it becomes an issue. Their happiness is lessened because they want to be something I'm not prepared to approve and frankly don't want to add. More subclasses, more bloat. More races, more bloat. More everything, more bloat. There is enough, already.
I understand: it is a business and has to put out content to make money. No issues there.
But there are other things I would like to see that for 5E simply aren't going to happen. One of the players will DM for the first time soon. He was asking me how does a rule work for something (I forget exactly what, it was a couple weeks ago), but my response was "Well, there really isn't a rule. You just have to make it up and deal with it however you feel works best." Some people
love that freedom in 5E, for others it is annoying as
HELL! The game feels incomplete to me because of such issues. There are other things I would like to see done, but I know aren't a priority for WotC so I won't see them...
I've said it before and I'm sure I'll say it again: the game used to be more about what your character
did, not what your character can
do. That might not make any sense... it is past midnight here so I am probably just rambling anyway. I'll leave this for now and revisit it in the morning when I have time.
Before I go I'll say one more thing. I would rather see more subclasses than classes. I think the core types are already there to build out pretty much anything you can think of and I don't think you need a class for every concept under the sun.
BUT (and this is a big but

) what I personally
don't want to see is
SO much overlap and making magic even more ingrained into each subclass (I'm looking at you, Wild Magic Barbarian or whatever!). To me, personally, part of the appeal of D&D is the mundane. Because then, when the magical and really heroic stuff happens, it is much more special.
I hope that clears up some of my perspective. I'll never fault WotC for trying to make money LOL or appeal to what their market research shows is what the broadest groups want, but when it makes things harder, or more annoying for me, then I'm not happy about seeing it...
Ok, I need sleep. Until tomorrow.