Richard, the stats from Pollock's "period of decline" (200-odd wickets at 25) compare more than favourably with the career records of greats such as Botham, Gibbs, Bedi, Benaud, Roberts, Snow, Thomson etc etc etc.
Just how you can describe him as "middling" in this period defies belief, particularly when by your own assertion it was achieved in the most batsman-friendly era in history
Pollock's figures between 2001\02 and 2006 are in fact 150 wickets at over 28, which is nothing more than a middling record. It's not poor, of course not, but it's certainly not remotely close to being outstanding, and hence he cannot be said to have conquered flat pitches the way Murali et al have.
In relation to Kumble, what the hell does "it's a classic record of a spinner who doesn't spin the ball much" mean? You're obviously making the mistake of comparing him only to Warne and Murali because it compares favourably to every other great spin bowler whether they turned it or not.
There've been very few great spin-bowlers since uncovered wickets ended, for this precise reason. Hardly anyone spins it enough to be effective outside the subcontinent, and almost all those that try to can't do it with enough accuracy (broadly these can be classified as fingerspinners and wristspinners, but as Kumble shows not all wristspinners are the big-spinning-wayward variety).
Ergo, Kumble, like most spin-bowlers, isn't a great, he's merely a great at home and mostly anodyne away (or roughly that anyway, there have been some exceptions).
"the bowler controls the game, not the batsman" - the opposite is true.
Err, no it's not. The bowler has the ball in his hand, how nonsensical to suggest the batsman controls the game.
As for the game being in a serious rut, how then do you explain that:
a. 5 of the best bowlers in friggin' history have played during the period in question
There have been countless hundreds of better bowlers than Pollock in history, and countless hundreds of better seamers than a mere spinner in Kumble.
b. The best ever wk/batsman is currently trotting his stuff
The Gilchrist of the last 4 years would be outstripped by any number of wicketkeeper-batsmen in history.
c. The best Oz batsman since Bradman currently occupies our no. 3 position
That Ponting can be considered such - so unequivocally - is indicative of the low quality of the period.
d. SL's best ever pacer is still playing
Vaas' presence is no gurantee of anything and never has been.
e. A couple of SA best ever (Pollock and Kallis) are still in the frame
Pollock hasn't been one of SA's best ever for a long while though.
In any case, there will be fine players at any time; there were far more in the 1990s, 1980s, 1970s, etc. than there are now. There are nowhere near enough good bowlers, and hence we cannot know how good the batsmen really are.