it's not wrong to only train a muscle possibly once every 7 days. some people need that much rest on specific body parts to feel 100% again.
however, your split is not beneficial for rest overall. you should have at the very least ONE FULL DAY a week where you do not engage in any lifting. this allows your body to recuperate. most people have 2 or maybe even 3
for example my split goes:
day 1- chest/bi's
day 2- legs/abs
day 3- shoulders/forearms
day 4-rest
day 5- back/calves
day 6- tri's/bi's
day 7- rest
this way you have at least 2 days for your body to
replenish itself. im not saying you should follow this split because everyone likes there own, but the 2 days rest are very neccesary.