The TB is truly a 'choke point' and probably the most effective tool over time to force an outcome (at least if people followed it). IMHO, the company is wanting to hire (and retain--at least up to the point their initial training investment is recovered with a profit) a slew of cheap button pushers under ever declining conditions of less pay and more work.
This business is heavy on initial training and certification (as well as in recurrent training to maintain certification) -- it takes a great deal of cost and time (yet the company would not want to realize this as a capital investment and do what it takes to retain experienced assets in terms of keeping them happy). There is no way around that. So increasing training assets under the present situation effectively subverts trying to maintain better conditions as someone gains seniority.
It's kind of like some regionals do in 'pay for training' -- only in a more subtile way -- those joining (and staying) under C scale effectively pay to train themselves and their D scale replacements through lower pay and worse conditions as they continue to work here.
Obviously the company is betting on the C scalers staying vs bolting (taking their training investment and experience with them). Which is why regionals typically have a high turnover rate and sometimes want the investment up front.
The keys to 'winning' are restrict the training assets and if conditions don't improve for those who gain experience and ratings to bolt for greener pastures when they can (assuming things do not get better).
There is a better way -- invest in your people and keep them happy -- but this doesn't seem to be the way of things as of late. As far as productivity is concerned the carrot works much better than the stick over the long term (one becomes accustomed to pain and how to deal with it and avoid it vice really working hard for the team because he or she likes what they do and their contributions). Seems a few folks running the place have trouble on figuring out where to put the carrot though.