Interesting. However for the purpose of this discussion it is both:

A) Irrelevant since it's not being run by a for-profit corporation, the kind that would care about these tax bills.

B) It's a bit of a cheat. TeX itself may be approaching an asymptote, but scientists writing papers in TeX do not use it directly or on its own. White it has created a reference upon which to build it has also externalized all that research and development into the thousands of accompanying packages which do keep receiving new features and need updating just to stand still.