Blame the state! A complicated, unwieldy tax code is their/our fault. They created an untenable system that got in the way of you entering into a mutually beneficial contract with another individual(s). It is 100% their fault.
Even the easiest tax system in the world won't make up for the fact that they need to record and charge for tax in that state, then send that money back to the state.
Short of not having sales tax, there really isn't a way that they can simplify it. And again, unless you are a lawyer that knows the tax laws in that area, you won't know how good or bad the local tax system is until you go to try and enter it.
It is weird - and I say this as an Australian - that an employer can be on the hook for employee's moving. it would be much easier if this was managed centrally.