So, my two cents here, trying to move away from specific people to a more generalized thing:
I think that it's a double edged sword in how we go about this. Either way, there's no real way to 'win' when it comes to 'people that other people don't like'.
Personally, I try and avoid Scarlet Letters. Each game is a unique space. They might share players, themes, hell, even code, but ultimately, each game is a thing unto itself. No two games have been perfect copies of each other. Even The Reach and Fallcoast are different beasts, for a variety of reasons, and that's the closest thing I've seen to a copy of one from another.
That goes for players too. I think that if we get into the habit of treating players differently based on past experiences or whatever, it's gonna lead us down a bad road. Players can have difficulties on one game, given that game's atmosphere and environment, that they'd never have on another. I've seen it happen before. While I don't buy into a lot of the 'hivemind' stuff, there is definitely a flow that you fall into based on a game's players, stories, environment, rules, etc, and like all social creatures we'll in some way conform to that, for good or ill.
This makes some people unhappy, sure. People who have been around for awhile and dealt with the same people can be wary, and with good cause. If you don't do what they expect, then you can catch a lot of heat.
But you can also catch a lot of heat singling out players for different treatment for any reason, and not treating all players as if they were playing on a level playing field.
There is no middle ground there. You either do treat them all the same, or you don't treat them all the same. No matter how you try and nuance it, it comes down to one of those two things. And either way, one side is going to be unhappy that you chose that path.
There is no right or wrong way to do it. It all depends on what you want from your game. Me, I choose to lean toward the 'all players starting on a new game have a clean slate, and will be treated as equals under the same set of rules'. Partly because I feel like that's the better option, and partly because it makes it less complicated. i don't have the time, energy, or desire to track the complete MU histories of the dozens of people that have A Reputation in this hobby. I staff on two games right now, and there are literally hundreds of players that I have to manage and work with. The ones with the Reputation are a small fraction of those.
So ultimately, I think that it just comes down to preference. And as I've said before, as much as we like to make it sound like MUers are a cohesive lot when it comes to certain things, it's just really not true. We're incredibly diverse, and we see it pop up all the time. We're just never gonna agree on certain things. And that's okay.
So that's my constructive two cents on People We Might Not Like.