Can of worms...
Would it be any different if they paid for their endorsements?
Or, they could take a reduced wage as they paid for the endorsement. Then it doesn't cost the company $$.
There is always a risk. The new pilot has the risk of getting an endorsement and PIC time to do charter. Does he/she pay or the company?
The company has risk (time as well as money) as they train up a new pilot, go through company Ops manual, route checks, etc.
Why did the pilots leave? So called grass being greener? Often it is.
If the company and pilot had better communication then it might not happen, "Hey I've been offered this, what can you do to match it?" If the Cp says, "Go for it, just don't come back..." Then go and there should be no hard feelings, the CP had his chance to match the offer.
I work casual for a company that pays $20/day. I know where new pilots are coming from, but I have talked enough with CP's to know there is another side.
But I'm still negotiating a better rate!
As for that Editor, don't get me started... (Doctors get a guarateed rebate from Medicare, that means they know how much they get paid from how many patients they see...)