If you're thinking of a reason NOT to buy bitcoins, well, my reasons are the expensive cost per bitcoin and how much slow and expensive the transaction time and transaction fees are with bitcoins. If having 1000 pieces of alt coins costing $1 each is better than having .01 bitcoins for $1,000 (hypothetically speaking), then I'd rather go for a thousand coins. I think I'll have a better chance of gaining a lot more money with that odds.