I think a large part of it is the region. Monster Hunter is a huge phenomenon in Japan, but it was barely acknowledged by gamers there on the level it is now until it went handheld. Monster Hunter belongs on 3DS because something about handheld Monster Hunter sets its biggest demographic ablaze like magic. Console MH sales in Japan don't even begin to compare.
And from the looks of things.. porting MH to consoles for western release doesn't see the sales that'd make the porting effort worth it. I can hella see why people in western regions prefer it on consoles, it is a "big" experience and seeing those huge monsters on a huge TV is pretty impressive at times, but the sales speak for themselves.