It has everything to do with dungeons though. You replied to a post discussing dungeons, and are instead bringing up PF related etiquette. (Edit: I'm saying the reply to the poster, not the overall thread)
The game provides you all the tools you need to play the game with the types of players that meet your criteria. You can create your own PFs and linkshells and network with the types of players who take the game more seriously... and that's fine.
But once you queue up into Duty Finder, you agree to play with the team the Duty Finder matches you with, or... take the penalty. If you queue up to someone else's PF, you meet their standards or... leave them and find ones that are more in line with yours. Demanding a particular skill level from the team you're randomly matched with, is a you problem, and in the other players' point of view, you're the selfish one, trying to hinder their fun, just to save a few minutes of your day.
Now, if someone without the skills, lies their way into your PF and ruins your day, then sure, complain all you want.
Perhaps it should, perhaps it shouldn't. The game is trying to appeal to a wide audience, with differing views and opinions on what constitutes fun.
Players who're interested in more difficult content will learn and do it regardless, players who aren't, won't ever care. Trying to force people into content they're not interested in, is how you lose your customers.
And not all players care about improving in their entertainment medium, nor should they. Having to do homework, look up spreadsheets and guides, and practice punching a dummy is boring, it's tedium, and all for what? Just to play a game to meet someone else's standards?
They're not dead weight if they're pressing their buttons and trying to do any damage, or if they're doing mechanics and happen to play suboptimally and/or make mistakes. If they're hanging around at the entrance doing nothing, you then have an argument for dead weight.