Sourceforge 1m ago : yes
Reason : sourceforge tried to deliver something other than the users wanted, either by providing two misleading advertising on the download page or even by bundling adware/malware.
elementary provides something some people want and in exchange asks for money. This is something HN actively recommend again and again.
elementary just happens to be nice on a number of levels from letting you decide the price yourself to feeding the money back into development.
I'll make a webpage where I'll sell elementary.io then.
Obviously, the money stays completely on my account, but don't worry, the OS comes with a few additional programs I wrote (or, rather, will have written), like a nicer IRC client.
I have my doubts about whether this will make you rich but as long as you are being honest and honor the GPL etc I see no legal or moral problems.
BTW: I know that I personally was not scammed and I would guess nobody else who paid for it felt scammed either.
I think many like me are happy to chip in with a little money as I don't have capacity to contribute code or support.
Bundling existing software with only minimal own involvement, and either scamming users with malware or by convincing them to pay?
Both Sourceforge and Elementary only produce a tiny amount of the code they sell (be it either a simple shell for a whole OS, or an install wizard for a most complex software).