Steels like Maxamet and S110V eat through grinding belts like nothing else, and take notably longer to produce. Also, the materials are not produced in the same quantities more common steels are, and have a higher material price. It's a lot of bother for a company to get into, and is honestly quite a gamble as far as profitability goes.
Spyderco is the only brand that I'm familiar with that will regularly take the gamble of rolling out models with extremely uncommon steels. LC200N, Maxamet, S110V, ZDP-189, K390... and those are just the regular production knives, not taking into account the nearly endless sprint runs of exotic steels.
In addition to that, they are typically on point with their heat treatments and grinds, and typically release these models at an affordable price point. They're a steel nerd's dream company.