Well, anything done enough times is a 'grind' rather than a game.
Unique special missions as opposed to dynamically-generated 'cookiecutter' missions take time to make, and I've yet to see a title have the spare time to make enough of these unique missions to take a character from start to max.
That having been said the mission system in general in MxO isn't terribly flexible at present. However, if you read the Producer's Notes you'll find that *gasp* this very system is being worked on.
Thing is that before even the first line of code is typed to make a system of this scale design decisions are made which for better or worse will follow the system into production. It's not trivial to tear these up and redo them.
So, don't ask to "Get rid of missions!" but instead ask that a more interesting mission system be developed which will eventually replace the existing setup. Looks like it's happening, so that way if you ask you'll be pleased with the results 