I also feel it's a way to make the many-worlds interpretation of Quantum Physics more substantial - I mean, when you have a working QC, if the results of the computation isn't arising from interference between the many worlds, where are the calculations being done?
I had a similar feeling until I took a course on 'Theory of Quantum Information'. It cleared up some reservations I had about problems of Quantum Computing, e.g. error correction, and showed, that these are solvable (at least in theory).
But more important, the lectures made it clear for me, that information is a physical quantity not less real than e.g. energy and that treating it as a non-physical "auxiliary" variable is core to many of the perceived paradoxes of QM. Also Quantum Computers try to make Quantum coherence work outside of closed laboratory systems, which not only pushes the boundaries of experimental physics, but also leads to interesting theoretical problems, since open systems don't exhibit a unitary time translation and are therefore not governed by the Schrödinger equation.
These things together helped to spark a new interest in looking at the foundational questions of Quantum mechanics after decades of "Shut up and calculate".