Frankly, from a customer service perspective, I think airport operators (airport authorities, etc.) ought to convince tenant airlines that they can provide skycap service more professionally and economically (rather than have several contract firms on the front curb.)

Then, the airport operators can hire whomever they like, charge $2/bag (or whatever), pay their employees a decent wage, and, implement a no tipping as well.

I see skycaps shakedown customers for tips at DTW every day and it disgusts me every time...