Because there are very, very few companies actually depending on Linux touchpad drivers in any meaningful way, and of those, most of those few are happy to take what they get for free and if they contribute at all (tiny tiny minority already), they'll rather do that with a more visible core component that actually powers their business.
Likewise, there's no established, dependable, working-at-all way to sell something like this. You can sell things like BetterTouchTool on macOS (a small utility that makes the Touchbar more configurable), because closed-source is fine on mac and people are ready to open their wallets in exchange for a better UX. That's simply not possible on Linux, everything meaningful must be open source and free as in beer (and, for drivers, probably free in all other ways, too), or it either can't work structurally or won't because the philosophy behind Linux and its ecosystem is incompatible with that sort of thing. Hence, it won't happen unless someone really enjoys doing this, or does it for their own needs and gives it away and maybe even supports it long-term despite of the negative experience that can be (entitled people etc.)
As for companies with employees using Linux, I guess quite a few shops would probably be kinda happy if the UX got so crappy it became unusable, because office IT for an an all-Windows shop is easier and cheaper to run – network printing just works for everyone, ActiveDirectory works for everyone out of the box, IT can ensure everyone is on the latest Windows update, security solutions run everywhere, everyone can use all productivity tools you could ever buy and you can roll them out easily using policies, no weird graphics issues that prevent people from presenting, no expensive "exactly this laptop with exactly that configuration" hardware purchases, one-size-fits-all tech support, etc. pp. This is also one of the reasons why WSL2 is such a clever move – make Windows the best (corporate) Linux around and get another large swath of developers to use Windows. It's also probably going to solve a lot of the Linux UX issues, but not in a way that benefits Linux in the least.