1. They are fickle feeders, you want a steadfast nom machine? Get a king instead, otherwise be prepared for winter fasts and lots of wasted rodents.
2. Not very active compared to most snakes, matter of fact, a happy bp will only come out at night most of the time. Possibly the worst display snake ever. Want something that's out and about more? Again, get a king.
3. They live 30 plus years, don't get one unless you can commit possibly half your life to one or get bored easily...
4. They are a terrible pet for most children. They need gentle handling, hate loud noises, fast movements make them nervous, and aren't awake during the day. Also see point number 3.
5. They are a poor choice for most beginning reptile keepers due to the above reasons and the fact that they require more humidity and warmth than most colubrids, and are far more easily stressed than most snakes in general. They are more of an intermediate snake.