You people are out the fucking gate. What are you even complaining about? If even completing a +15 at all is more difficult than 95% of people can ever possibly hope to achieve, why do you even care? Do you get this angry about playing football in your backyard and not being able to compete for a premiership? Why can't you just be happy with pugging a 7 or whatever and stop trying to ruin things for the people who can do a +15?
I haven't got a problem whatsoever with people who push whatever content they find the most difficult, even if that is doing a +4 and just barely scraping in with one chest. That's awesome, good on you. But if that same person turns around and says that the entire game mode should be changed so they can do a +5, instead of improving their own play, getting better gear, or socialising more (in a social game) in order to play better tactics, then I have no respect for them whatsoever.