Exactly. I'm not saying anything at all about other people using smartphones, just that I personally have little to no use for one. Case in point:
Of course that anything you can do on a smartphone you can do on a pc. Doh.
That's like saying one has no need for a car because the lorry you have on your garage does the same ****.
Can you carry your pc in your pocket though? Can you skim twitter whenever and wherever you are with just a touch on a screen rather than having to turn on your pc and wait several minutes till you get to open your browser at home?
I unequivocally loathe Twitter, and while I do use Facebook, I can't think of any reason why I'd feel so urgent of a need to post that I'd do it on the go. I'm fine with waiting until I get home to post a status update or read what people are doing. Lord knows I spend enough time on my PC during my average day, so I have plenty of opportunities to do so.
This is easily the worst argument to not get a smartphone I've ever seen. For this to be even somewhat credible you'd need to literally never leave your home. If you did, you'd need to tell me that smartphones are not worth the money. Yes, they're expensive, and it's totally legit to not want to get one because you don't think you'd get your money's worth out of it. But telling me that smartphones are unnecessary because you have your PC? Total bull****. You're not going to carry your computer to the grocery store so you can look up a replacement when they don't have tamarind paste, and you're probably not going to pull out your laptop for that either (this is all assuming you can find wifi, or have some sort of expensive cellular dataplan for your PC anyway, obviously). And for the people who prefer to carry around physical books, you're not going to lug around a 20 volume encyclopedia on the bus or keep it in your trunk so you can look something up on a whim (forgetting the fact that when you leave home you're almost never doing nothing but sitting in your car or on the bus).
Quite honestly, I don't leave my home all that many times during my average week. I'm only working part-time right now, and that work is done via PC, so I'm always here to look up info. When I do go out, I'm almost always the one driving, so the only thing I can do then is listen to music, which I have covered via radio or MP3 player. I can't think of any time when I've needed to double-check some piece of esoteric info while out and about...I generally don't go shopping without having a clear idea of what I'm buying first, and I'm not exactly enough of a chef to require the sorts of things that a grocery store could possibly run out of.

The one universal statement I will make about smartphones is that I find touchscreens to be a pretty godawful user interface option, particularly at such small screen sizes, unless one is using a stylus. And I'd like to see the mobile browser that could handle having a few dozen forum tabs open at once.
