Hi Apple,
I think that's an unfair generalisation based only, it seems, on anecdotal evidence. Yes, I'm a broker and so "I would say that, wouldn't I?"
But I also would have many friends and acquaintances in the mortgage broking business who wouldn't dream of selling out their clients in this manner. Many of them are fairly low-profile and run very successful businesses from referrals from existing clients alone, with no need to advertise. So apart from personal ethics, it can be very financially beneficial to treat your clients well.
The sort of carry-on witnessed on Prime Time (and by your friends if you're talking about the same practices) is unquestionably wrong, but to label a whole profession with a sweep of the brush "most other brokers" is excessive, in my opinion.