They were purchased that way. The ASA does a lot of testing, so they would approve a bat and then you would get a bulletin that an approved bat failed follow-up testing and was now illegal. There are A LOT of illegal softball bats on the market, at least there were 5-6 years ago.
Again, it comes down to who you are. If you are playing in a Co-Rec league, you probably don't know if your bat is illegal or not and the ump probably just wants his $33 and couldn't care less. If you are playing in a Class A qualifier, you probably do know if your bat is legal and if you don't your opponents will surely point that out to an ump who will care.