Sure, but risking a small step back for a huge step forward is a pretty good gamble, IMO. I mean, if you bet $100 for a chance at $1000 with decent odds, that's a great bet. If you lose, you can be criticized for losing money, but that doesn't mean the decision-making was flawed.
We can, of course, debate whether he had decent odds or not (I think NateBishop thinks not, which is fine), but if you feel you do, it's a good decision. Only Bosh knows for sure how seriously he was considering Houston, but I don't think it's unreasonable to believe that he was seriously considering Houston. Just the fact that he went back to Miami doesn't mean he never considered Houston.