It’s not about identity as much as it’s a very poor way to try to convince someone.
Don’t base your line of argument on a statement you know the other person will likely disagree with.
For example “You should play Pathfinder because DnD sucks”, holds no weight to people who don’t think that DnD sucks. In fact if they happen to like DnD, it undermines your argument, because if you disagree about DnD, aren’t you also likely to disagree about Pathfinder?
If they play a system, they probably like that system and find its shortcomings acceptable. You can’t convince someone that a system isn’t enjoyable when they have first-hand evidence to the contrary.
Asking people to stop being comfortable doing something they like, so that they can be uncomfortable doing something you like, isn’t a good value proposition.
If you lead with “Thing you like is actually bad”, their immediate response will be to disagree with you and start defending the thing they like. And if you want someone to listen to your arguments, rather than just try to poke holes in them, you must avoid putting them on the defensive.
To get through to people, find common ground and build off that. “If you like FEATURE in GAME, you’ll probably love SIMILAR FEATURE in OTHER GAME because…” is something that’s actually going to get someone interested, rather than start a pointless argument 
Well there are no crits on checks in 5e, so a nat 20 +0 is no different from a nat 6 +14. And someone with a +14 can’t fail a check with a DC of 15 or lower.
Having Degrees of Success built into the system in PF2 is really neat though. And seems like something DnD could easily incorporate if Wizards had any vision.