If you mean that maybe bitwise operators shouldn't have been included at all if javascript was only going to have one numeric type which would be floating point

If you mean that maybe bitwise operators shouldn't have been included at all if javascript was only going to have one numeric type which would be floating point, maybe you're right. However they can be useful as long as your integers or bit flags are smaller than 2^32 (or 2^31 depending on what you're up to), just pretty slow as every operation needs to do a double->int32->double conversion. on the other hand, -0 and +0 are a pretty straightforward result of the normal floating point representation, are sometimes useful, and IEEE 754 defines +0==-0. Hiding them under a single 0 would have been more of a hack than having to deal with the difference very very occasionally.