I think this is a golden example of how to reply to an accusation: lay down the facts, don't get down to the mud, but clearly expose the other side's errors - with class!
After first releasing the entire application that used some GPL code.
Generally if you are infringing on copywrite, you just have to STOP infringing and you are good.
You can't embed gotcha clauses that say "if you break this copywrite, you have to pay me a billion dollars".
Whether they stop infringing on any further sales of the software is of no consequence to me and to the software they already sold me.
IANAL.
That is, indeed, a good way to respond to an accusation.
It is not, in any sense, what Wix did. The response was free of facts, snarky, and didn't even address the claims the other side made, much less expose any errors.
What Wix needed to do was say "oh hey, good catch, we'll be compliant soon" or "thanks but we think we're compliant". They did neither.
But (the following is not you specifically :) but I can't just edit my original post) I got several negatives... They are not meant to show disagreement, if I'm not mistaken. Please remember to comment when you down vote if you see my comment as against the policies - otherwise there is no way to improve HN comments.