Some stats on spinners in 2008, particularly for Richard:
Most Test wickets - 4 spinners in the top 15, including 3 finger spinners (and Monty Panesar)
Best economy rates (min 100 overs) - 10 spinners in the top 20, including 7 finger spinners ( & MSP)
Most five-wicket hauls (min 2) - 6 out of 12 are spinners, including 4 finger spinners (5 if you count Mendis) (&MSP)
Best average (min 150 overs) - 6 in the top 20, including 3 finger spinners (+ Mendis)
Best strike rate (min 150 overs) - 6 in the top 20, including 2 finger spinners (+ Mendis)
The point isn't "finger-spinners are obsolete" or even "Monty Panesar isn't very good". It's more that he'll either be massively effective (see Old Trafford '07 or '08) or horribly ineffective (see the South Africa tour up to the dead rubber, every match he's ever played against India). It's usually pretty obvious when he's going to be super-effective and when he's going to pretty useless, so why pick him every time?
I think that was Richard's point.
It isn't - fingerspinners still have a place. However, that place is no longer "most grounds" which it used to be in the days when wickets were uncovered.
Fingerspinners have always needed the right pitch to be effective. When pitches were uncovered, these happened often, everywhere. These days, the only place such surfaces occur regularly is in Sri Lanka and, to a lesser extent, India. In other countries, you can easily get whole seasons going by without one Test on such a surface.
MSP had a few more than normal early in his Test career, which gave quite a few people the impression he was better than he was.
However, you can tell a fingerspinner to "attack" as often as you want on non-turning surfaces, he still can't take wickets. The only way a fingerspinner is ever going to get wickets on a pitch that isn't of the right type is when they're gifted, which doesn't happen all that often. If, as a fingerspinner, you try to attack when the pitch doesn't allow you to, all that'll happen is you'll go for lots of runs. So on an unfriendly surface, your choice if you have a fingerspinner is basically between 25-60-1 and 25-112-1. So if you keep picking fingerspinners on the wrong sort of pitch, they'll all end-up being simplistically dubbed "defensive" bowlers. Because once you actually get into the match and realise the realities rather than the ideas, you're pragmatic and tell your fingerspinner to bowl defensively.
MSP can only attack on the right type of pitch, exactly the same as any other fingerspinner.