Generation III saves the games to flash memory so a battery is not needed for saving purposes (Ruby / Sapphire / Emerald have one for the clock though... I'm not sure if FireRed / LeafGreen have one at all).
Personally, I see where Pikaminccino's coming from, but I don't exactly agree with it. I want remakes or ports because the games are fun and I'd like to be able to play them on a newer system... the battery itself doesn't really matter much (especially if I'm done with the game and could care less if the battery dies or even leaks... and if I'm not done with the game then I'd still prefer to be able to play it on the newer system anyway, regardless of any technical problems caused by a battery (i.e. even if there was no battery or no problems caused by the battery, I'd still like a port))