Oh the theoretical aspect is important.

But applying it is important as well. Of course, most quantum computing algorithms have not had a chance of being implemented; it's not always possible

Or, as Knuth put it "Beware of bugs in the above code; I have only proved it correct, not tried it."

But if someone comes up with a paper showing a new algorithm but doesn't come up with an implementation of it when it would be straightforward to do so, I begin to doubt this person.

Most other fields don't have the luxury of easy testing.