Because you hunt monsters?

it's bounty hunting, but with monsters.

You kill boss monsters and regular monsters for body parts to build and upgrade equipment

No leveling, atleast not in Monster Hunter Tri, for Wii.

I tried it, but got bored rather quick myself.

just my opinion: for me a monster kill LOL without having to use magic or experience as well as those rpg games, only your experience of using the weapon you won the fight, one wrong move will die, the armor is also essential you can hold much their attacks, so you can dodge his attacks depending on the effects of armor
and also that the armor when you complete your set you get good effects to facilitate your mission for example your defense, speed of your weapons, protecion attack that kills you, bear elemental attacks, mysterious effects (as well as that the new jinouga armor effect that even I do not know lol)
the creative of the game is the monster can be small, medium, large or giant or legendary that this makes the game more challenging
especially the part you can play online with other players with the same mission
and also call attention weapons also have special items or you can knock the monster or shoot have many options to accustomed your battle style of this game

Note:note just my opinion no offense other game or anything like

Fight monsters, get bigger stuff, so you can fight bigger stuff with more people because it gets more difficult... or something like that.

Personally, I'm not looking for the "You must be THIS HARDCORE to play this game" experience. I like having a gaming experience where I can play and not worry about "Do I have all purple elite gear, otherwise I'm useless in PvP/PvE/PvPvE".

So yeah, fun is good.

Hai there~
The main thing I like about monster hunter is that, there are no leveling thing there. You tend to experiment on armors and equipment to obtain the mix of skills you want to have.
Compared to WoW, some similar traits I hate are the "grinding", when in WoW, you hope for a specific weapon/armor to drop. For monster hunter, you hope for a specific item to drop in order for your armor/weapon to be forged.
But overall for me, the two are very different games