That's odd...
... I'm pretty sure my Atom based NC10 Netbook is currently rendering a complex comp in After Effects while I'm listening to MP3s and typing this. Yes, I know its not as fast as a full blown desktop, I knew that when I got it, but its massively convenient and literally goes every I go.
The NC10 is also not below some pretty heavy online sessions of (the admittedly old, but still very much active) Unreal Tournament with everything turned up full and with TeamSpeak running... even when tethered wirelessly to my phone!
My netbook has even been used to DJ with in nightclubs/bars, with a hardware controller, controlling intelligent lighting rigs and providing video for the clubs/bars screens... sometimes all remotely controlled via VNC on my phone, great for when nature calls or you want a drink.
So what were you saying about the Atom?
I'm willing to bet the only Netbooks you've used are ones loaded with shedloads of cruft, dragging them down to the point of uselessness! I know someone with another Samsung netbook who has a ridiculous amount of unnecessary "helper" services running in the system tray and an (IE) browser window literally half filled with dodgy toolbar addons. You can imagine what the rest of the machine was like... I gave up trying to advise the owner of that particular machine!