Let's say employees are often uninformed about the circumstances. When you hire me and we agree on, let's say $25/h it seems to be fair at first. Later I find out you bill your customers $85 for my work and have a $10 overhead, I might rethink if I made the right decision.
You describe a common problem in the construction business.
Employees discover that the contractor marks up their work,
charging far more than the employee is paid. The employee
feels unfairly exploited. They never understand that the
contractor takes all the risk of unpaid call-backs, pays to fix
the employee's errors, faces customers who don't pay,
covers all the overhead of tools, trucks, facilities, payroll
taxes, liability insurance, unemployment insurance, etc.
Without a profit, there's no reason for the employer to
ever hire you in the first place.
I know so many of these guys who strike out on their own
so that they can earn the big bucks. Then the reality sets
in....their skills on the job aren't as good as they thought
without the experienced contractor guiding them...running
a business is much harder than performing a trade....to
design & enforce a contract is much more difficult than
anticipated....collecting debts is harder than they thought.
$25/hr paid vs $85/hr billed is a pretty reasonable margin.