Ah. I see the problem here. You are mistaking a court of law for society outside its doors. The criminal justice system must treat any subject before it as innocent until proven guilty, the rest of us do not have such restrictions. We operate is a fuzzy place where reputation is a strong determinant in whether heresay matters, where a pattern of suspicious behaviour is sufficient to decide not to associate with someone, and where OJ actually did kill his ex-wife.
I'm curious what you think about private discrimination on account of race, then (e.g. when hotels and restaurants were turning away black customers, back in 50s in US - not because the law said so, but because they could).
Discrimination in commercial transactions within the public marketplace are illegal (c.f. Katzenbach v. McClung, et al) and discriminatory membership requirements for "private" clubs that operate in public is unpleasant, but I have no idea how to fix that particular problem legally so we solve it with the previously noted social pressure (aka "mob justice") and this seems to work reasonably well. OTOH, the state does not get to tell you who your friends will be or who you should be spending your time with.
They are illegal, yes. I was wondering whether OP also treats it as "just freedom of association", since fundamentally refusing to serve some customer for any reason whatsoever is exactly that - and yet most people would agree that, done on such scale, it violates people's rights, too.
There's a difference between discrimination - ie, different treatment based on the group, class, or category to which that person is perceived to belong to rather than on individual merit - and choosing not to associate oneself with a specific individual.
I think you, in turn, are mistaking the legal concept for the general principle. We have the legal right to be presumed innocent – true. However, most people would additionally advance the principle that we, outside legal proceedings, ought to expect hard evidence to accompany allegations of wrongdoing.
