I would imagine it's rather similar to the reasoning for Twitter, etc. banning people; it's a private company/club so they can decide who they invite to use their service/play their tournament.

Even a few seconds of Wimbledon is enough to make me homicidal and want to sweep through the stands with a flamethrower. Just thinking about it while typing this is making me clench fists.

This makes them look pretty pathetic though. Funny how sport and politics can't mix when it's, oh I don't know, Cricketers going to apartheid South Africa, or Celtic fans waving Palestinian flags, but when it's rich plummy ####s banning Russians because of their government, that's just dandy. The glaring hypocrisy of the "rules based order" is so massive that people who've never thought about it before must surely start to wonder.