I didn't really disagree with the first two, but concerning the third one, that's really not true in all places in Europe any more and a little bit of a stereotype. Berlin is very much a cosmopolitan city at this point, and Sweden has always been very open as well. As is London and even cities like Warsaw are becoming more and more accepting.
France and Italy as two very large countries stand out, the former because it's very closed up culturally, the second because it's not in a good shape politically.
I won't deny that the US has a more open culture (having experienced both myself as a German citizen who has worked in the US) but the gap is not so large any more that the generalisation is valid without qualifications.
Ok, so we agree Europe is so much worse for a startup person.
Sure, there are many nice cosmopolitan cities in Europe. If you want to get a few year-long stint doing whatever - not a problem.
What happens once you get children? Are you going to send them to a local school and have them grow up speaking a language you hardly know? If you're Jewish aren't you going to worry about your children getting hurt? If you're an Arab aren't you going to worry about your children being othered? If you're not a Christian, can you fully practice your religion? (i.e. some European countries ban kosher slaughter, there are plans to ban circumcision, burqa bans, Poland just made talking about some parts of the Holocaust illegal). How certain are you an EU citizenship will mean a thing in 10, 20 years? How strong are your property rights? For how long has your European country of choice been a safe, welcoming place?
For some people these aren't big problems, that's okay. For those that do worry about these, they aren't being picky or unreasonable. US is simply a better, safer deal.
France and Italy as two very large countries stand out, the former because it's very closed up culturally, the second because it's not in a good shape politically.
I won't deny that the US has a more open culture (having experienced both myself as a German citizen who has worked in the US) but the gap is not so large any more that the generalisation is valid without qualifications.