I always picked Charmander. In Gen 1, it looked cuter than the other two, and it became a dragon. What's not to love?

Furthermore Charizard will have tougher time trying to taking on Lorelei, Fire pokémon didn't resist Ice type in gen one, and Lance.
Is that why he kept getting frozen? This explains much...but it also raises more questions. Why aren't Fire Pokemon resistant to Ice Pokemon in Gen 1? Was it a mistake, like the Ghost/Psychic Pokemon?