I think that a lot of the people that actively believe in supernatural things tend not to like to use inflammatory terms like atheist.

But a lot of people that do not believe in god are interested in 'spiritual energies' or something similar that really amounts to a supernatural belief.

I tend to agree. Most people I know who would label themselves as an atheist, myself included, do not have any supernatural beliefs, unless you get ridiculously nitpicky on the semantic side.

The term itself doesn't exclude belief in the "supernatural", but it is (as far as I can tell) claimed largely by people who don't have any belief in the "supernatural".

Since when is "atheist" an inflammatory term?

I don't consider it to be, but it certainly is for a large portion of the USAs population, mainly due to differing interpretations of what the word means, and the common perception (at least in small-town USA) of atheists being amoral as well.

It's kind of like "socialist" - many people think of it as inherently bad, instead of just a different set of relative values. I've lived in Sweden and can say that atheism, agnosticism, and socialism aren't bad, just different.

Exactly. It has a lot to do with the ambiguity of language, particularly english.

It is inflammatory. Not only to the religious but also to the very large percentage of people who see it as a strident position.

For something to be inflammatory it only needs to inflame.