We didn't need them at the time, and there were questions about the proper way to go with this.
In fact, these functions came out as we were using them from the umath_tests, where inner1d and innerwt are implemented for float32 and float64. We wanted an accelerated version of inner1d implemented using BLAS sdot and ddot. We also made a version of innerwt to have both together.

We thought about adding a complex version. In BLAS there are two different versions of dot for complex numbers. [cz]dotu and [cz]dotc. Probably is dotu what would make sense, but as there was not a clear choice we just skipped this. If there is a consensus on which one to use that would be great (and quite easy to add). There is the option of supporting both with, which would involve a bit of extra effort. In any case, it was even less clear which would be the right option in the case of innerwt.

Really open to suggestions in this point :)