Why would you think it's wrong? Virtually EVERYBODY who makes their living in the reptile trade resells animals at one time or another.
I know that there are certain individuals who have been running a campaign to demonize resellers and are trying to make the label 'flipper' into a derogatory term. Don't buy into the hype.
It's not the widespread practice of reselling snakes that is the problem, it's how certain individuals go about it that is the problem.