Yes I understand this.There isn't a big enough market for them, they are made in low quantities and sold at a high price. Roel_koel would have a slightly different opinion being as he was a professional freerider and now imports banshee into the UK... But most people can't justify that bike in their stable. It can't race 4x and its a bit too little for a mini-dh bike and its too short for an xc bike. They are expensive and niche and while everyone would love one, other bikes might be a more sensible choice.
But for people who know exactly what they want and have the proper venues to ride them in, there aren't very many options....that doesn't mean the market doesn't exist. Like I said.......specialized has sold out of their SX frames within about two months every single year over the last 5 or so. Why? Because they're really good bikes and spec doesn't go too far out on a limb and overproduce them.
If a bike in this genre is GOOD, and the company can put a run out that ventures into the profit zone because they didn't overstretch their resources, they will sell, and the company will make money. The segment is growing. It will never be as big as the trail bike or even dh bike segment but it's worth doing because there is in fact a market, and a shockingly pathetic list of quality options out there.