MSQ is fine as a healer because the bulk of the MSQ isn't about group combat where a healer is needed or even combat in general. It's about the story.
It's weird that so many healers rail at YoshiP's comments when there is truth to them. The healer role exists basically to cover the butts of the players who like to stand in fire.
When am I most engaged as a healer? When I'm playing with a group of fair to bad players. I have to actually heal. When am I least engaged as a healer? When I'm playing with a group that knows what they're doing and can execute mechanics correctly. I end up nothing more than green DPS.
Make the mandatory content too difficult and the former group can't progress, which is bad for a MMO. It's the casual players of average or lesser skill that pay the bulk of the bills for game development. Without them, there wouldn't be high end content for those who want the greater challenge.
Perhaps the reason they're "dumbing" it down is they're seeing a large percentage of players hitting barriers with difficulty that are causing them to drop out of the game.
Whether or not you feel the same way, most people aren't playing for some sort of personal validation from their skill level. They're playing to relax. Some of fine with a small bit of challenge. Most simply want to just make their way through the game with a minimum of hassle. When they're in the mood for personal validation, they seek it in their real life pursuits outside of games such as career, education or family.
If you need a game that keeps upping the skill level each time a challenge is passed in the base content, MMOs are the wrong place to be looking. They can't afford to keep increasing the skill cap in the base content if that means players will start leaving the game. That's why those challenges are placed in the side content.
If the complaint there's insufficient difficult side content, then that's worthy of a separate discussion.
You always have the option of playing as DPS if that's what you feel like you are.