Idealistically and realistically: Totally and absolutely cool.
If anything, they have a moral imperative to keep the project going, since there are users that depend on it, and doing that requires money.
As such, people will need to be informed of how to contribute, so a pop up doing just that is a good way to achieve this.
Why would this not be ok, even idealistically?
Ideally speaking: totally not cool
Realistically speaking: they got solid stuff going, and plus you can disable it one way or another
Idealistically and realistically: Totally and absolutely cool. If anything, they have a moral imperative to keep the project going, since there are users that depend on it, and doing that requires money. As such, people will need to be informed of how to contribute, so a pop up doing just that is a good way to achieve this. Why would this not be ok, even idealistically?