That experienced captain isn't a check airman and shouldn't be a babysitter. I've said it from the start, the right seat of a jet airliner with 50+ paying people onboard is NOT the place to learn how to fly an airplane. Captains aren't there to babysit, they're one part of a two man crew. If the guy next to me is a wet behind the ears zero experience kid holding onto the tail for 4 days, they're of no use to me or to those on board in case of a real emergency. It's one thing having an experienced pilot with no airline experience trying to figure stuff out for a few days. It's a whole other thing having a zero experience pilot try to figure everything out, from "How does an ILS work" to "Why are people yelling 'guard' at me when I talk on the radio?"

Not to mention that pay will be cut and the whipsaw/race to the bottom of the early 2000s will be back if the 1500hr rule went away. All of us civilian folk have had to work our way through the world of aviation and building flight time. This isn't some new thing and honestly if you're willing to work, getting to 1500hrs isn't that difficult, especially right now. There's countless charter, surveying and CFI jobs out there again that can provide priceless experience to a young pilot. Go fly some airplanes in real deal IFR and get some experience before jumping into an ERJ with auto-everything.