Probably because he's a proven Serie A scorer and we get one over on Inter, and we've been after him for years.
It's like we weigh up the age, dodgy recent injury record, poorer recent form, cost and history with our club and think that's a fair trade lol.
If we're genuinely after him, of course...
I always thought he would age poorly, he's massive and will get more and more muscular injuries.