Sadly, there will always be people pulling "All lives matter"-esque b.s., even on the Left. What's even sadder is that they've (consciously or otherwise) bought into the Right-wing narrative that not including every group equally when showing support is exclusionary to people or characteristics that are not in fact in need of that support, but also, as we see here, sometimes even taking the stance that only they get to determine the version that is 'properly' inclusive, not anyone else.

To wit, if the standard Pride flag is meant to represent everyone, equally including cisgender straight white folks, then it's by definition not a symbol of especial support for marginalized folks. If it's not inclusive of cisgender straight white folks, then who else is it not inclusive of, if the colors aren't actually being mapped to specific groups?

It makes perfect sense to me why variations have emerged, and there's no need to try to pare the field down artificially. New flags emerge all the time, and fall in and out of use. Flags are a choice about how you present yourself, in choosing to fly them, and it's not anyone's place to be telling other people they are beholden to use a certain flag.

"We have a flag that represents you all, but your communities don't get to decide if it represents you, or if you would be better represented in another way, you listen to me!" - Such a very inclusive mindset! /s