Stop the bonding issue? Slavery and feudalism? What utter rubbish.
I think its perfectly fair for a company that is good enough to pay for your TR (given the fact that some companies make profit on your training!) expects a return of service, to offset their investment in you.
Lets not forget that a military pilot has a 12 year commitment in the UK, or 16 in some instances.
When you say 'let them come after you' in a vigilante fashion, maybe you forget that such (perfectly reasonable) bonds are legally binding. Your
unique and idealistic view would get you laughed at when the legalities kicked in. Not to mention the fact that I'd guess no airlines would touch you with an 'unspent' bond, due to possible legal complications unique to you, and indeed the fact that the VAST majority of airlines who pay for your TR expect a bond too, so you can guess what they would likely think of you.
Or would you leave an airline under a bond, to another airline whereby you would be required to pay for your next TR?
Paying for a TR (rightly or wrongly) is a fairly modern practice (in todays scales, at least), bonding is most definately not.