Yes, you could be left behind even more, but if your group isn't willing to help get you back up to speed and instead just tosses you to the curb, it wasn't a very good group to begin with was it? A good group will help with those catch up clears making it go really fast.
I have plenty of friends that would love to play an MMO that simply won't pick one up currently because their current field of work and the cap systems that MMOs use for end game content are incompatible. Their schedule fluctuates in ways that make it impossible to static, and if you pug on weekly capped content, this can happen quite easily, and its also why guilds developed their point systems.
I would bet Avraym feels behind progression wise and thats even with meeting the weekly cap.
The fun of military work or other jobs such as those that work in oil drilling and the like where could be running into situations of couple of weeks of near constant work followed by a couple of weeks off, or schedules that fluctuate on a very regular basis and can't have set days off like with typical shift work. Which is a nice chunk of potential players that might not touch some harder content as often as they might want to as they are limited much more on when they can play and the caps don't really account for them. These are the ones who would benefit the most from the removal of caps, along with those that might be taking a vacation for a couple of weeks. At least without an enforced cap, groups with a member that falls into one of the above scenarios can plan around it, and delay the clears until they can do it as a group instead of loosing the loot chance for cap cycle.
And the point you raised about maximizing playtime for best effect. Why do you think people started making guilds and statics in the first place? It wasn't to exclude people, but to efficiently clear content in limited playtime for those that are unable to play more than a few hours at a time. Yet weekly content caps can still impact them and put them behind as well thanks to all the same factors that affect any individual.