Believe it or not, there are people whose opinions on market regulation differ from yours.
Why would it be fortunate to be compelled to do business with someone who's suing you?
Fortunate for those of us who don't wield monopoly power over a marketplace.
Does the little guy enjoy doing business with an adversarial customer any more than the big guy? I can't see why that would be the case.
So that your legal rights aren't undermined. Especially companies dependent on single large companies have the legal system as their only protection against abuse.
It sounds like a double-edged concept.
This regulation sounds like it could create a channel for abuse. Specifically, if someone sues me, then I can't fire that customer for any reason.