Not really, there are 2 types of botters, there are the ones who do it for personal gain of time. Botting to get some herbs for raiding, pvp honor ranks for mounts, gear etc. A permaban here and you usually lose these customers, where as a temp ban will frequently reform these customers as they do not want to lose what they worked for prior to botting. These are the customers you do not want to lose if reformed because they turn into a good customer, frequently. There will always be the bad apples in this bunch but the escalating severity of the ban may at one point work(some repeat offenders are at 24 months now, basically a permaban)
Then there are the ones who do it to make money, real cash and this is easy to do because you either have bots that are scanning the AH for miss-posted stuff(there are tonnes of these) people who misses a zero on a spectral tiger, or under cut on a new BOE too steeply and make 100K gold a day or the farmers that use bots and speed cheats to farm herb and or and make gold that way and then resell to the gold market for real money. You can make a lot of money quickly by doing this and when they get banned on one account they open a new one. it is simple as that and no matter the ban type they will always make money because you can not ban them fast enough to not make money as it takes time for Blizz to build the case to ban them.