If it's true then it is a "big" deal because a few hours earlier he said that he will definitely be there, how important it is for him and for America blablabla and then minutes before planned travel he decided not to go and play golf instead. Come on.
Various politicians from all around the world decided to fly at low attitude in military planes to be here and he's one of like 17 or so who declined. And that's after years of feeding Polish people how important we are to America, that we're one of their biggest strategic partner, friends etc. etc.
But again it's politics. He should be signing a condolence book by that time. It's a big deal here where national mourning is a very important thing for most people. Most older people are mourning, crying and whatever and while I find it stupid he knows that they do.
Personally I think it just means that Obama doesn't give a shit too much but it doesn't offend me in any way. It's just that many people will feel offended and he should know this. I think it was a pretty silly thing to do after all and I'm very liberal if it comes to politics. I don't care about it that much. But not even a condolence book or a visit in Polish embassy? That's not nice.