Except Ascended gear doesn't just provide an infusion slot. It also has higher stats than exotics. If Arenanet just wanted to please the dungeon divers, they could have added Ascended items with just the infusion mechanic.
The issue or lack there of one, is that Ascended Gear contributes only marginally (if at all) in anything sub-80. That miniscule stat increase is nigh-irrelevant in any of the other content due to the down scaling and the only places it will have an effect are:
- PvE: Arah & Orr, and SSC
On the PvE side of things, considering that people had no problems running around in greens and yellows, should have no problem now running around in exotics (which have become even easier to acquire to the point where they are almost literally being given to you at 80). There was a phase shift from green/yellow vs. full exotic to yellow/purple vs. (currently all of three pieces) full ascended. So long as the content has no checks (much as Fractal has no checks, you can run the first 6 levels in green MF gear), then no one is "losing" out on content because of this gear. The only thing lost is going deeper and deeper for better and better rewards... but that opens up the can of wurms for effort vs. reward.
On the WvW side, issues are larger but currently non-starters. A back piece and two rings aren't suddenly going to break a large team format. With increased rewards (particularly in the badges department) and, with a timely introduction of WvW Ascended, the problems should be largely alleviated, people will be rewarded for WvWing, and (for once) WvW might give people a sense of progression (though it will certainly need more).
Why did they add this tier? To be honest I can see the reasoning. Exotic Gear didn't have much of a "special" feel to it and could be bought, so any and all effort behind it was more or less vapor. Ascended is account bound for the key material, so you cannot just "buy" it and, in the WvW scenario, you cannot buy badges either. Probably, what they are/were going for was to make a system akin to the WvW system of badge earning: play the format, earn the special gear. If they hadn't added some "increase" to the Ascended, it would have just felt irrelevant so they buffed the stats.
Note: I'm not trying to justify, just rationalize.
Edited by Var, 19 November 2012 - 11:49 PM.