Well, I have a pretty 'dumb' phone ... SE K530i. Had it for years, and it's really good at ... making phone calls.
Much better than the nearly TOTL K750i I had before. And probably better than an iPhone.
And I have a Palm M515. Actually, I have four of them, plus an M500 and two extra batteries in case all of the others have worn out.
Why?
1) I don't feel like paying for a data plan. And I have a (non-data) carrier plan with a monthly basic rate of zero (okay, I admit it's a >10 y old plan for journalists with a 100% rebate on the monthly basic fee). For making phone calls, I rarely ever pay more than 10 Euros in any month.
2) I need a portable organizer (= PIM), but don't feel like putting my personal (PIM) data somewhere on the net.
3) I can lock down the PDA, which I can't do with something that also doubles as a phone.
4) I prefer putting my files on an encrypted USB thumb drive rather than on Dropbox, Evernote, or the like. Although I have to admit that both are tempting.
5) I have two pretty nifty cases for the M5xx form factor:
a)
Palm Leather Wallet case. b)
Kensington aluminum hard case. So sturdy you can let a tank roll over it.
6) The battery of the PDA lasts for more than a week. And the one of the phone for several days.
7) I prefer reading paper books. Especially as my eyes don't get younger.
Those cases are actually the main reason why I had Palm Tungstens and a Win Mobile 6 smartphone gathering dust unused. I've never seen anything like those for one of the touchscreen-smartphones. I usually use the one I feel better suited for the situation. And I still have spares for those two as well.