If an anime Pokemon died, I'd be sad, especially if it was highlighted in the series.
In the games, if I KO wild Pokemon, on a moral view I'd be sad, but on a gamer's view, not really, 'cause Pokemon Rangers and Nurses (and Breeders?) will just come by and use a [Max] Revive on the Pokemon. But if one of my Pokemon died, especially if I invested loads of time in searching, capturing, (IV/nature) breeding, training (for EXP. & EVs), and/or soft-resetting for it? I'd be totally pissed off (even if they're just "pieces of data", no offense, that means I technically wasted huge chunks of time that I'll never get back :(). Also, if said Pokemon was my starter, I'd be even more disappointed due to the experiences I went through with it, the time I spent with it, and our strengthened "bond" from defeating supposed "pieces of data". :)
However, if I had a flash cart and was able to use Pokesav for legit reasons, that'd be a totally different story. I actually would feel less disappointed! :D