if there doing so good why dont they put it on the PSP 
Because 90% of the current players would loathe the changes in culture and gameplay it would bring about, and 90% of the PSP players who tried AH2 would hate it because it isn't the arcade-style shoot'emup they're used to. it would mean the death of AH2 within two years, max.
I'm not saying everyone on PSP is lame - it's just a very different player base and culture. A game like AH2 has an inherently limited but highly devoted player base, and companies like Sony and Microsoft want nothing to do with that sort of thing for their consoles, which is why they don't offer anything remotely similar. The sort of revenue AH sees is a drop in the ocean for them.
I'm just glad and grateful that HTC exists and provides us with so much fun. The worst thing that could happen would be for one of the megacorps to notice them and this community - they'd inevitably either buy HTC out or crush it, then promptly take the game off the market. That's what they do. They don't want niche markets to exist, they want everyone spending every entertainment dollar on their blockbusters. And love of the genre or the history plays no part whatsoever in their cold financial calculations. We saw this in the board wargame community; Hasbro bought out Avalon Hill (the preeminent wargame publisher for decades) only to take every one of their wargames off the market.
