It's a kids game. It's not very well interpreted when they hear that their Pokemon died. xD
In Lavender Town, yes, there are dead Pokemon.
However, Game Freak try to keep the topic of 'Pokemon death' out of the games, due to the audience they are facing it at. For example, if an 8-year-old kid's Meganium that they EV trained so much just got decapitated by a Bisharp, I think we'll have to witness some waterworks.
So really, it's just the audience Game Freak is facing the game at. It wouldn't be very suitable for younger kids.