This is a really tricky issue, and I can understand why the Supreme Court ruling doesn't go as far as the disability campaigners might have hoped. It stopped short of making it compulsory for people to give up space to wheelchair users, opting instead for a transfer of responsibility to (in this case) bus drivers.
Drivers will now have to consider a further step to pressurise passengers who refuse to surrender space, depending on circumstances, and that pressure may extend to "refusing to drive on" until the request was complied with.
Being confined to a wheelchair is bad enough, and having the additional stress of worrying about boarding a bus or train must make it much worse. That said, the court's ruling is not going to remove the potential for arguments at bus stops, and outcomes are still going to depend on individual drivers' judgements.