It's about getting a clear statement form the US government that this can be ignored at no risk to them aiding in enforcement.

I.e. peace of mind. Not just for the large~ish (questionable in various ways, as the lawyer points out himself) sites currently under fire, but for all the minor ones that simply don't have the resources to comply with every country.

(I haven't read today's article) in a previous blog post, they did mention that geo-blocking the UK was not enough for ofcom to stop the harassment. So having a clear statement, and potentially using that as angle to accuse Ofcom of harassment should they not stop, would be quite welcome.

While the US has a great track record with protecting their own citizen against legal threats from the outside (maybe a bit too much at times), I'd love the same to be done in the EU, since I'm a lot more doubtful about our relations with the UK in such aspects.