The acquisition would make sense. If I were NetApp, only 2 aspect of the deal would raise concern:
1) do I want to get into the tape business?
2) what to do with the 2000 employees of Quantum (and at what cost).?
A number of sources whisper to The Register that tape-maker and dedupe specialist Quantum is in negotiations over a sale – and they also say a well-known Sunnyvale storage supplier is fingering its wallet. Three Reg sources have said they've heard Quantum has a "for sale" sign around its neck. So, just as a thought experiment …
Quantum is a company that came up with some good stuff but just couldn't deliver. A lot of it's stuff was not very good and was not supported well.
Netapp is a company with a history of having difficulty integrating new acquisitions and technologies into it's portfolio.
I think while Netapp could afford Quantum I'm not sure it could do a lot with what it got. There's no immediate profit and as a user above commented they will have 2000 employees......a large chunk of which they will have to get rid of.