First of all, everything I say is IMHO. Second of all, even if not literally true, that is an accurate statement of how I feel about those movies, so by saying it I'm explaining where I'm coming from. Thirdly, as a viewer, I'm not obligated to "accept" everything I'm presented with. If I don't see how it fits the bill, I'm perfectly within my rights to explain that, esp. since I'm not forcing it on anyone. If you like those movies, fair enough.
The question I have with any major change to a franchise is how far can it be twisted before it becomes something different? Maybe I should've put it that way, but when seeing those movies, it's lacking somehow.
I should qualify my comments.
I think a valuable criticism of anything, Trek or otehrwise, is more like, "X doesn't work because [insert reason that is more than just "it's not Star Trek"]. Because you can't have a very interesting discussion about who thinks what is "real" or not. I'd rather have discussions about what the work is saying (or failing to say) or how it's saying it (or how it's not) etc. Debates about legitimacy are rarely useful and generally just people talking at each other about their own boundaries.
What I really take umbrage with, what really makes my skin crawl, is when Trekkies say "You are not a real Trekkie if you just watch the Kelvin movies." It doesn't look like you've done that, so this criticism isn't directed at you. But it's related -- it has to do with gatekeeping -- setting boundaries around what is "real" and what is "poser Trek" or "fake Trek." I hate that stuff. It's exclusionary. For all the hemming and hawing Trekkies go through about making Trek more popular and successful, we sure have a funny way of making the problem worse by being gatekeepers.