Because such a software is not something that I own - I'm at the mercy of the software creators, hoping that they will sell me the software as long as I need it

Because such a software is not something that I own - I'm at the mercy of the software creators, hoping that they will sell me the software as long as I need it. And they disappear more often than not, leaving me searching for something else that helps me. Sometimes I like to check the past submissions on HN, what was trending a year or two ago. Vast majority of the "look at this cool SaaS Product" submissions is a dead link. But don't believe me - see for yourself. I'm not against paying, I do believe proprietary software has a place in the market, but I'd rather pay a bigger, 1-time sum for guaranteed availability over paying smaller fee for a longer time, while hoping that there will be still a company to accept my payment next month.