main reason why products are discontinued usually is that it's not worth for company to maintain old product if user base is small or decreasing and product is

main reason why products are discontinued usually is that it's not worth for company to maintain old product if user base is small or decreasing and product is not profitable anymore. Even if company is not actively developing new features in that software, still it requires maintenance - fixing bugs, updating libraries to keep it working with new OSes and so on, and it has a huge cost, assuming that there are big teams dedicated to products. Also sometimes vision changes for whole company and existing products does not fit that vision anymore and company decides to kill it. Regarding "never changing" software idea: it inherently is doomed because by default user base will be shrinking - majority of people would move on newer (with better features) software and only handful of users would continue using old "not changing" software. It's jut not worth it, and is too small niche.