I'm a fairly new bay12er, been playing DF for about a year now, but never really participated in the forums until this last release. Anyway, here's my 2 cents on slipping standards. I agree with some about paid off reviews, but a lot of reviews are preliminary reviews where the designers show off the best parts of the game and then the review is made, so in a way it is biased. Most reviews are this way. So it's easy to give a horrible game a good review based on being shown the best parts. I think that graphics also play a large role in games, but feel as though this has been happening for a long time. Ever since the computer became a household item, people have been trying to improve on graphics and make the "Most fantastic graphics EVER!" game. Though personally I feel like graphics are nice, but shouldn't out-weigh gameplay.
Lastly, I don't disagree with numbered scores, but think it should be standardized, much like someone else wrote in here. Such as (just a suggested scale) 1-2: horrible graphics and even worse gameplay 2-3: horrible graphics, but slightly better gameplay 3-4: bottom of the barrel graphics but improved gameplay 4-5: one-time playthrough gameplay despite graphics 5-6: one-time playthrough gameplay with improved graphics 6-7: Good gameplay despite graphics with average replayability 7-8: Good gameplay with good replayability and decent graphics 8-9: Gameplay is amazing despite graphics, easy replayability, learning curve is simple, but keeps the game depth deep 9-10: Playing this game is highly recommended, and playing it over and over again is even higher on the recommendation, oh, did I mention the graphics are good 10: Game is a must to play and replay and graphics are state of the art, if you don't own this game, your not a gamer.
Well, that's just my opinion. As far DF I only give it an 8, mainly because of the learning curve. I've been playing a year and still haven't figured everything out, and just now have gotten brave enough to work with magma without committing to suicide. Great game, and even better replayability, but one hell of a difficult learning curve.