This whole good/bad care character stuff is a silly rumour that kids seems to like circulating - possibly as a bit of an ego booster when they get a character they like.
I can tell you now, for every person that say "I got X character by totally neglecting my tama" there is ALWAYS another who can say "I got that same character and I looked after my tama perfectly!". ^_^ You are already experiencing this and if you read around you will see the same.
Stop worrying about a silly rumour and start having fun with the unique character you have!