Oskar,
you see this move all the timed from what I remember at $10nl, and I see it now from the maniacs who pop up in $50nl.
They get to the river and miss the flush draw or realise that they have nothing. The only way they see to make you fold is to push all-in. And they feel like a poker god when you fold. They feel like a twat when you make the call with TPTK.
and yes they do push with 2 pair here also, but they also shove with so many other hands that I call in these spots all day long.