I don't see the problem with it at all. It's all relative. You need to appreciate thier target market. It stopped being for regular 'proper' nightclubbers a long time ago (99 by my reckoning
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)*
First of all, this is a Ministry comp*, so take the actual wording of the title with a pinch of salt (considering your own pre-conceptions of what is the underground). This is Underground 2008 just like the Annual is a 'collection of all the proper club hits of the year'.
There are some undeniably awesome tracks on there, and if you were the sort of person that was stuck buying Hed Kandi/Ministry/(cheesier end of) Defected records, then you aren't in Underground nightclubs, and so this could be a tool for you to broaden your horizons. The fact that some of the track as 2006 isn't really a factor as you don't go to the nightclubs that rinsed them way back when.
And then let's face it, why would MoS release an album for the Ministry-Album-Buying-Public with the design brief of havign an album that woudl aim to bring/show them out of the niche of all that over-produced girly nonsense, without using the 'tried and tested underground' tunes, if you'll excuse the oxymoron.
*Disregarding of course the recent Sessions comps, as they look a touch acceptable, though I've only listened to one of them (Mark knight!) and that was more of a crime against my ears than this could ever be!