It's really sad when a company has no place they feel comfortable referring their clients. It suggests they either:

Don't trust us (clients/customers) not to like Plan B better -- but deal with it. Because if we do, then learn from that and adjust your business accordingly.

2. Think they're so head and shoulders better than everyone else that no one is good enough. Then get over yourself, let us know that the referral is just an option, and let the buyer beware.

Of course, as you point out, there's a third way: Bury your head in the sand and pretend that nothing's ever going to go wrong. That's the worst option of all because your clients/customers have referral networks of their own.