If I understand correctly, one of the main arguments behind condensing the MSQ is being unable to play with friends/friends giving up on the game too soon.

I myself invited two friends to the game. As I said before, I've recently completed HW (not the patch content), and my two friends just now finished ARR (also not including the patch content). They are nevertheless the target market of the game - drawn to story telling, so going through the narrative and doing things step by step doesn't bother them at all. And I've hyped them, so they are eager to continue. They also have less time to play than I, so I believe if we had started at the same time I'd probably still be ahead of them.

But the point I'm trying to make is: I'm not expecting them to catch up to me. Instead, I invite them to do old content with me. Old for me, not for them. I think it's better for me to adjust to their level and what they have unlocked so far, than pressure them into rushing through the game. Plus, they are my friends, so I still have fun doing lower level dungeons and trials with them. And seeing them fail at mechanics. And sliding job guides their way. :P

I think that's a good way to encourage friends to play with you and keep them engaged. If you invited them to play, you should adjust to them instead of asking them to adjust to you.