I think it serves a very important purpose, to the point where even if it’s considered in some way “wrong”(vaguely) in various circles I’d think it would be in everyone’s interests to fight against that for it’s use. It’s supposed the use of “LGBTQ” as an adjective for someone on the “spectrum”(the language around that needs discussion too, but for clarity’s sake I’ll brush past it for now) that doesn’t specifically mention a part of their identity which they, for whatever reason, should not, cannot, or just don’t want to disclose. It completely bypasses having to worry about adding more initials to the moniker, which was a kinda ridiculous subject to have to discuss for what should be a simple adjective, and it’s a fundamentally pleasing word as pretty much everyone that actively uses it seems to agree.
Though honestly it seems like the discussion around it is more… academic(?) than anything else, since the decision about weather it should or should not be used has already been made: people are using it. Like, I don’t know anyone I follow on twitter or talk to in real life that doesn’t use it without thinking. A lot of those people would get confused if you questioned their usage of it, then just go back to using it. Language change is a thing that happens naturally, and rarely rarely do attempts to influence it on as grand a scale as the complete removal of a word from general use aren’t usually successful.
A lot of objections to it come from people who have had bad personal experience with it, which is fair in so far as it’s a perfectly reasonable natural reaction, but people have also had bad experiences with “gay”, “lesbian”, or outside of just queer stuff, “autistic” is one I can talk about personally. I’m pretty used to it’s flippant use as a synonym for “stupid”, probably because it’s more fun to say, and it’s use like that isn’t exactly brilliant, to say the least, but I’m not going to stop using it because of my experiences of it being used against me. Getting worked up about it and desperately trying to get people to use some other term when talking about it, because 1: that’s not going to work, and 2: making the technical term for something into a social faux-pas is making the thing itself into a social faux-pas, which isn’t something you can allow with autism.
But also, yeah, what @Shivoa said. One of the favourite pass-times of right-wing internet basement dwellers to is try to make people believe that something innocuous is Bad™ for fun.