I don't see it as a matter of trying to wedge our little niche back into motocross. To me, this is a moral issue. Of course, the closer we can get to equal, the better, and as such the 150 v 250F and 300 v 450F is an improvement. Equal-or-Nothing is certainly not the right approach, because it means we'll get nothing. However, I still don't think that any inequality is desirable. To make an analogy that's WAY overpowered, let's imagine that the current situation is like slavery. The two-strokes are getting the short end of the stick and the four-stroke reigns as king, laughing its ass off. 150 vs 250F is a big improvement over this, but it's still not the ideal, just as segregation was an improvement, but not the ideal. What I, and I think all of us, want is equality, for all bikes whether they be two-, four-, or even six-strokes. Make it like every other fair motorsport in the world. Give X room to work with, and he with the most efficient machine wins. If that means that four-strokes get eradicated, it's just because the four-strokes aren't good enough. There's nothing special about four-strokes, or two-strokes for that matter, that says they need to be preserved and kept on regulatory welfare to remain in the sport. In the past, two-strokes were allowed to compete freely, and virtually kill off the four-strokes. What was the result? The biggest period of growth and technological development in the entire history of the sport - a time when everyone and their cat rode motorcycles off-road, and almost all of them were two-stroke. Not because two-strokes were singled out and given special treatment, but because the machines themselves were superior.
In every other realm, besides motorcycle racing, that's how it works. Nerdy, socially-awkward people don't get a relationship stimulus from the ministry of girlfriends. Railroads running steam power don't get a tax credit to make up for their higher overhead. And overinvested banks don't get bailed out with taxpayer mon... hmm... well, that is to say, they shouldn't get bailed out by taxpayer money. I think that the best course would be to collect our relatively scattered forces together, and form an alternative racing organization that embraces this equality and doesn't act as an extension of the Big Four (or Five if you count KTM as big enough.) Will it be as big as the AMA in year one? No. Will it be as big in year five? Probably not. Will it ever be as big? Who knows, but at least it will exist, because right now it's infinitely smaller than the AMA. The vintage racers did it when AHRMA lost track of what matters to their members; it can be done.
That's my take, anyway. Sorry if I started to sound a little too much like Ayn Rand.