I'm of mixed feelings about pre-approvals.
These days, most stand up fairly well. There's still a handful of lenders that have a high probability of not honoring a pre-approval, but most are fairly good.
For the majority of people I deal with, it's completely unnecessary. We look at their income documents, their assets and liabilities and I can make the assessment fairly easily and accurately on what the banks response will be.
Then occasionally you get a curve ball. In the past 2 years I've had 2 occasions where the client had a default they didn't know about, nor would have reasonably predicted. It wouldn't have changed the outcome, but it would have made things a little less stressful when they made the actual purchase.
That said, pre-approvals can be a significant amount of work, and about 50% either don't go ahead, or expire and need to be resubmitted later. I can understand why a lot of brokers don't like them.
Consider that it takes about 3-10 hours work for a pre-approval (both in submission and follow up). Let's assume an average of 5 man hours.
Assume the broker is reasonably successful and writes 30 pre-approvals per year, in addition to all the other loans they write.
50% go nowhere or need to be resubmitted because they've expired.
5 x 30 x 50% = 75 hours of work wasted per year, or 9.375 working days.
It's not the end of the world, but try telling your boss that they're going to pay you for 9 working days this year and you'll be completely non productive.
I don't really mind pre-approval, in fact we do quite a few, but there are some guidelines I like to follow. Generally I tend to look at the circumstances of the application and make a recommendation. Loans over 90% LVR it's always a good idea. 80% or less it's not a big deal. 80% - 90% is a grey area.