I agree with Mike Emery in that article. Here's my take on it. What I see is that the segments of the sport have become much more defined. Back in the day, you went to either the CRA or AMA tracks and you raced. That's all that was available-- that was what MX consisted of.
Now, we have to take a few things into consideration. There are still the old stand bys. Then add riders that only go to practice tracks, vintage guys, Vet guys, etc. Sites like this, and the internet in general, have provided access to far more information regarding what events are happening beyond what we had 20 years ago (which consisted of the CRA schedule that we stuck to the refrigerator every February). The MX cake has gotten a great deal larger in comparison to the amount of icing we have available to frost it, so we have to spread that icing thinner in order to get the whole cake covered. That's why it seems like the events are more sparsely populated.
If the manufacturers are looking at bike sales as indicators, then you have to take into consideration that the new technology has stagnated slightly in the past decade before the past year or two, so alot of riders have been racing 5 or more year old bikes successfully.
We're forgetting that a kid that knew how to ride, showed up at LL on a 25+ year old bike and almost won on it. There are Bomber, 2 Stroke, 125 classes out there, so the cost of the bikes shouldn't be that big of a factor. Gas prices may be an issue to an extent.
If you NEED a $40K motor home, and a 3500 diesel truck to pull a couple of brand new bikes to race, then yes, cost is paramount. If you REALLY want to ride and race, a used pickup truck and a 15 year old 125 will get ya on the gate for $5K. A set of gear can be had off of Ebay for $75... Problem is all that frugality isn't fashionable.
It's my humble opinion that alot of guys want to talk about riding and racing, but for some reason, they make excuses instead showing up and actually riding. Other than that, I think the sport is alive and well, and the diversity helps the draw, and it keeps guys in the sport that would have been out to pasture at the same age 20 years ago. --L*64