What doesn't Dell have? A public cloud
Why should they?
It's like asking why doesn't Tesco own McDonalds.
Or why don't Unilever, Nestle, Heinz-Kraft only run restaurants. Eating out will never replace eating at home.
1) Inevitably there will be a small number of Cloud sellers = Hosted Services. They need massive private international fibre networks, that's why there will only be a small number of vendors of hosted services.
2) It's a completely different market to selling mostly hardware.
3) HW sales will not go away. Clouds need client equipment.
4) HW sales will not go away. Much IT should NEVER be on the so called Cloud.
5) Setting up datacentres, global networking, managing services etc is quite different to making storage arrays, servers and PCs.
6) No doubt the laptop, PC, Server and storage markets are challenging. They won't go away and doing something unrelated you know nothing about is no solution.
Apple has had iTunes since before iPhone. It made the iPod successful (which was very late to market MP3 player). Phones and tablets are a consumer commodity product. I expect Apple to try and sell their cloud services to non-Apple users. Dell abandoned their phone and tablet lines and Apple has maxed out. Apple's not Dell's future is in Cloud services. Apple has been doing this for 16 years.
IBM disposed of their PC, Laptop and then x86 server business, but really before the x86 was unexpectedly a success for them, their mainframe business was about selling on site managed hosting / services. The Cloud is just that at a datacentre (warehouse of pizza box style computers instead of a single mainframe shared) via the Internet. Nothing new.
SoundJam MP, developed by Bill Kincaid and released by Casady & Greene in 1998, was renamed iTunes when Apple purchased it in 2000. Jeff Robbin, Kincaid, and Dave Heller moved to Apple as part of the acquisition, where they continue to work today as the software's original developers. They simplified SoundJam's user interface, added the ability to burn CDs, and removed its recording feature and skin support. On January 9, 2001, iTunes 1.0 was released at Macworld San Francisco