i think I phrased that badly, as no, nobody should dictate over others - but I can see ebikes being problematic within established groups. I'm newish to the area, so have joined a workmate and his mates - so there's about 5-6 of us. Some more serious than others, but we all have a laugh and are unified swearing away on the long climbs etc. As soon as someone turned up with an ebike there would be much p-taking (which is fine), but I could see it could lose an element of camradery, if suddenly that person isn't "suffering" in the same way as the others, if 4 ppl are struggling together in granny gear and 1 person is barely out of breath with their bike whirring like a bee. Hell, it can be demoralising enough to be on a long technical climb and have a random whirr past on an ebike, so if they're part of your group, I can see it being divisive. Sure, you could tow people up a bit, but then they lose a sense of accomplishment by achieving/earning the climb.
I'm not against ebikes, they're great to get less fit (and disabled) people out and enjoying mtb-ing, or to transform the route options to be twice as long (or have double the climbs) etc. But, if you're doing a ride with non ebikers then I (personally) think it's more fun, appealing and team-bonding to all be on non-assisted bikes.