Like a number of other service businesses with reputation problems - plumbers, locksmiths, garage door technicians (no, really) - it's a service which customers only need very infrequently, and where the customer is typically under pressure to choose a vendor quickly when they need service. There's very little repeat business; as such, there's not a lot of pressure against dishonest or substandard vendors.

There are so many variables. All it takes is a few able bodied guys to start up a company and prey on people who need to move, sometimes short notice. If a job gets screwed up, no big deal, just start another company or have another friend do it and team up.