There are nuances here in Florida. For example, if you accept a postdated check you are considered on notice that the funds are not available and thus, no intent to commit fraud exists which leads to no criminal charges.
The Florida Bad Check law also applies to cards and other payment instruments. Florida is plagued with fraud, and there are schemes involving debit cards, money orders, etc. which boggle the mind sometimes.
Removing the check laws would expose a vulnerable section of society to a different type of fraud. So while the checking system may go away, those looking to exploit the poor will simply do so with cash, which is practically untraceable. At least a check gives investigators a chance to develop a paper trail for those who cannot get a credit card.