Being poor I feel like I've always focused on the treadmill aspect of a lot of MMOs. Especially with early MMOs like Everquest, it really seemed like they were slow as a way to keep you engaged just enough to keep you subscribed.
I remember being in the City of Heroes beta with some friends. It was actually genuinely fun leaping around rooftops as a Hulk-sized mountain of muscle I called "Herbal T" (a riff on Mr. T). I remember when the beta ended, they ran an event where an alien race called the Rikti invaded the main plaza of the city. My computer back then was not anywhere near adequate -- a Sony Vaio with a hand-me-down GeForce 3. With 300+ players all crowded around the town square, my framerate was so low that you could count individual frames on your fingers. In fact, my framerate was so low, the server would sometimes kick me because my system took too long in between drawing the next frame.
A year or two later, armed with a better PC, City of Heroes launched a rerun campaign where lapsed players who used to play (or were in the beta) would get a week of game time for free as a way to hopefully lure them in to a sub. Remembering how fun and fresh the beta felt, I eagerly downloaded and joined my friends...
...Only to see the treadmill in crystal clarity. All they wanted to do was their daily/weekly grind missions. The fun of exploring the city and punching thugs off sky scrapers was gone as we warped around using fast travel, walked three feet, and were thrust in to a dungeon where they skipped most encounters and focused only on the handful of specific mobs/materials they needed.
That was maybe 2005 or 2006, and the last time I ever touched an MMO, to this day.