My point was that if those people are known troublemakers and they have a protected characteristic, what then? You might be able to exlude them after they've done something wrong, but you wouldn't be able to exclude them purely because of a fear that they might be a problem, even if experience tells you that they will be. Not because they are Travellers per se, and not because you are a racist per se, but because they have a reputation for anti-social behaviour that goes before them and something about their demeanor in your presence is making you uncomfortable.
Whereas in TR's case, it seems the restaurant/pub can sling him out based on his reputation alone, and 'feeling uncomfortable' even though he did nothing wrong while there.
If you did that to a specific group of Travellers who you had read/heard bad things about but had not personally experienced any issues at all, you'd almost certainly risk being sued for racial discrimination.
I do know what a protected characteristic is. And yes, some people do have them, some people don't, so I am not sure what you are driving at there. 