And what if LinuxCNC looses interest? They are not payed and not working on this full time, so they are more likely to loose interest than a company like how you loose interest in hobbies. Same with grbl and other free stuff done by hobbyists as a hobby.
Centroid company can loose interest the same way as the UCCNC company can.
UCCNC is around for about 5 years or something like that and the company is 20 years.
I think these relative small companies will only loose interest if we will not buy their stuff, then they will fail go to trunk and the heavy industrial gold expensive stuff will remain and the opensource which will result expensive stuff or hobby half baked stuff and hope for support.
I see opensource this way but again maybe it is just me. And my point of view is general about open source not only cnc related.