I think bolstering is brilliant. It eliminates long queues and allows low levels to immediately get in on the action. They are weaker than true high levels too, so while still being able to participate, you will get your face owned off. I do not speak about this with any experience whatsoever I promise ...
Also, just because you like end-game does not mean everyone will be looking for end-game. Not everyone enjoys rushing immediately to max level to start raiding; some of us enjoy the journey there. Plus, it's sort of ridiculous to criticize end-game raiding for a game that's not been released yet, of which they haven't mentioned the other end-game material yet.
Just my .02 credits.