No, i think we understand that we are entitled to have opinions and favourites in competitions.
Has Kelly Holmes been 'cut down' for being successful at the Olympics? No, because she was running for herself and for the country as a whole, so everybody gets behind her.
Do Man Utd get slated by non-Man Utd fans for being successful? Yes, because they have fans who support them, and then those who support other teams and, as such, rightly or wrongly, automatically critcise them, regardless of their quality or ability.
When someone choses to 'compete', be it in sport, music or the like, there should be people who 'big them up', like them and support them. There will also be followers of their 'rivals', some of whom can accept 'losing', others who cannot - to say, for example, that every G4 fan is bitter towards Steve is wrong - yes there are those who are but the majority are not.
I think, also, it is a trait of people that when their 'favourite' wins, they are blinkered to the bad things about them and only see the good - i find it hard, for example, to critisice my favourite football team, even they play awful (which at the moment is often) - and i can get into a debate with someone about it, and whether i agree or not, will still 'stick up' for them.
I think there are those who like to 'bash' people who are successful, but i wouldn't say it is a 'National Trait'.
God, that was my longest post yet i think!!