I can see that going either way. If I had no other option an otherwise highly finished home undergoing rennovation, I might do that too. You don't really ruin anything taking the hood down (assuming a common range hood) to access the jbox.
I would pass it. NEC 2008 314.29 says it has to be accessible.
Art 100 says not to have to remove any part of the building finiish or stucture.
So I agree with Marc. Depending on the type of range hood.
The electrician most likely didn't plan it this way. And would probably not have done it if the wire had not been to short.
It's fairly common to conceal a junction box behind something that is removable. It could be a recessed light. A range hood may qualifiy as well depending how it was installed. See Art 100.