These aren't game mechanics, they're psychological hacks. Classic game designers used all these 'mechanics' as a sort of spice, to enhance the solid gameplay already in place. Games like Farmeville are refined and condensed spice. No meat, just flavor.
Personally, after playing Diablo as a kid for god knows how long, I vowed to never play a 'grinding' game again. I suspect (but definitely am not certain) that most new casual gamers will go through their own experience, and come out the other side more immune to these hacks.
Of course, I was the old Total Annihilation buff. I had a few mods on it, mainly adding up to 1000 units per side, and up to 10 players.
The most I played was 6 sides, each of us around 800 units each, with 200 en route to someone elses base. Those games lasted for around 5 hours, which were a blast!
Then we compiled a private epic build system on top of advanced that had mechs, berthas on wheels, and walking fusions. The doomsday device was a nuclear launcher that would, on impact, destroy a 22 screen radius of everything. When you're playing on Real Earth v2, which is 128x128 screens (at 1024x768) you need big skills.
None of this "click on buttons to make xp go bigger" or other gimmicks of these net games.
I'm generally more interested in the 'motivation' aspect of Game Mechanics. (see profile for startup info) The 'fun' you speak of in FPSs is a bit different than the 'fun' that can come from a normal web application which offers some sort of incentive or status for your contributions.
This is totally missing most of the fundamental game mechanics that make FPSes fun, platformers fun, etc.
In fact it misses out much of what makes WoW fun for end level raiders.
Re-reading it this feels more like a deck of false rewards to make people think they're playing a game when they're not.