Frozen mallet isn't the problem it's the cancer champs who abuse it
Frozen mallet isn't a problem on 99% of the populus, the problem is when stupidly broken sticky champs like Gnar and Yasuo come along (No resource, retarded amounts of mobility and cc) comes its a 100% guarantee you will not get away unless they want you to.
Gnar has a cc on every ability on his kit. Couple this cancer with frozen mallet and he can't stop chasing you.
Seriously, frozen mallet isn't the problem, just gut the cancer champs already.