IIRC, Olly Kohn arrived in rehab and was injured for a long while before he started playing consistently. And then he was fabulous for several years until Wales finally broke him beyond repair.
Quins physios certainly used to have a good knack of refreshing the players other clubs couldn't reach [1], though they seem to have lost the golden touch a little. The club has been pretty loyal to its injured players, which has paid off several times through players staying when they were offered much more to leave, and it has also been good at giving them a decent exit once it's clear they won't recover. In an attritional sport like rugby, I value that.
As a parent of two children who have dreams of playing professional rugby (however unlikely those dream may be), I would not want them to play for a club that would treat them like consumables rather than human beings. If that comes at the cost of worse results sometimes, then I am actually OK with that because I think it pays off more often than not in the team spirit that it engenders.
And quoting Brian Clough just reminds me that this isn't football and I don't want it to be.
[1] Something to do with Heineken, perhaps?