[xorcist]

It used to be completely free hosting, that's one thing that was great about it. Same thing made Sourceforge so completely dominant that it took many years for projects to move off it even after more suitable alternatives were made available.

But the main use case was probably convenience. It's a very quick way for Mac and Windows users to get a small Linux VM up and running, and utilize the copious amount of software written for it.

These days it's mostly standard, for better or worse. There are a handful vendor independent ways to distribute software but this works with most cloud vendors. Is it good? Probably not, but few industry standards are.