So I guess there needs to be more understanding on both sides instead of blaming. I'm quite sure none of the two "sides" wants to be offensive... it's just different countries with different opinions.
This. The UK is a place where "The Pub" is the only place where people can escape their usual strict social rule set. For many Brits a con is like going to the pub with good friends.
I have no doubt that any of the headless guys would have never have done that in the city centre. But they'd do it at the con for the same reason as a continental fur wouldn't have a problem losing the head when at home.
I had a similar debate earlier today about Kigus and why in the UK they're fine at some events where in continental Europe they'd be seen as unsuitable for the hotel/con.
For Brits, while at the con, this is as far as there concerned, their home that they share with some mates for a while.
At least that's what I think, knowing both Brits and Germans ^.^
A lot more people these days also talk in suit. Also a big no go not to long ago.
Personally I'd keep my head on at cons. But that's my choice to make, and someone else's is theirs to make. Fursuiters are there so they have fun. If you also have fun because of it, good, but it gives you no right to make demands.
Edit: That said, I agree with Dhary that we should try and "educate" in this case. I don't mind headless suiters, but I love a good con video as much as everyone, and headless guys in lots of shots are not ideal.