My vastly overrated rambling opinion....
First off, idiots like the one earlier today are going to come and go here on /r/abdl. Best thing to do is immediately report them, and the only proper comment is "Obvious troll is obvious". Don't give trolls the attention they want.
Now, to your point. IMHO, Too many people think they are the gatekeeper of what their particular kink is, whether it's ABDL, S&M, foot fetish, yada yada yada.
I always think of it like George Carlin said concerning drivers: Anyone going slower than me is an idiot, and anyone going faster than me is a MANIAC!!!
There are ABDLs that will behave in ways the vast majority of other ABDLs will not approve. For example, there are ABDLs that knowingly go out and defecate in the diapers in public and purposely walk among others to get a reaction. While most of us hate people who do this, like it or not, those people are still ABDLs. On the opposite side, there are others that claim to be ABDLs and wear the occasional diaper, but never use them. Those people are ABDLs, too.
For me, I try to remember that there are all sorts of ABDLs that may partake in activities that I don't find enjoyable, or activities that I find dumb to do. For example, I think it's dumb to try to become completely incontinent: bladder, bowel, and flatulent incontinence. But those that are trying to do so are still ABDLs, and I have to acknowledge that there are ABDLs that do things that may not be as socially acceptable as I'd like them to be. I'm not going to dismiss them or say they aren't true ABDLs (no true Scotsman) just because I'm not on the same page as they are with their fetish.
Speaking for myself, I am not incontinent, and I am sexually attracted to diapers. There have been those in the past that want to exclude people like me from being considered an ABDL because people like me make the non-sexual crowd look bad. Tough titty. I'm an ABDL.
This doesn't mean we can't try to talk some sense into ABDLs that may be doing things that have a negative impact. We should tell an ABDL that trying to have their sphincters surgically removed by a doctor in a 3rd world country is a bad idea. We should tell ABDLs that want to run around Disney World in just a diaper and a pacifier that they shouldn't go through with their plans.
But like it or not, these people are ABDLs.