98 people out of every 100 could run Linux as their main operating system tomorrow, and the 99th person could run it in 6 months when (X app) they are waiting on is finished/upgraded etc.

However, people have varying levels of excuses they use not to do so.

I can get all the software I want

Linux comes with all the software you need on the installation CD. With windows you have to pirate it, or buy it. Why spend several thousand dollars for software that comes on a CD with Linux?

It doesn't run Microsoft Office

CrossOver? Wine runs Microsoft Office just fine on Linux. There are also lots of office replacements under Linux; OpenOffice, KOffice, Gobe Productive, Gnumeric and Abiword etc. Many people prefer these over the Microsoft counterparts because they are less likely to try and outthink you all the time (For instance, none of them have paperclips...)

It doesn't play my games

Perhaps, check GamingOnLinux, many popular windows games can run using one of the various incantations of wine. Or perhaps buy a console and play games on that.

It doesn't have Photoshop

Not natively no. But CrossOver? Wine runs PhotoShop 7 reasonably well. TheGIMP is suitable for a lot of peoples graphics needs if they don't mind learning a different application. But if it must be Photoshop and you want to us a Wacom tablet then Windows or MacOS is your only real option.

There is also a very nice Photoshop clone that has been ported to Linux. It's nonfree, but A LOT cheaper than PS... check it out at http://pixel32.box.sk -- TomHibbert

I dual boot back into Windows and never find a reason to go back into Linux

Well, try removing Windows from your computer totally. You'll feel better, I'm sure.

The reason that the answer to all these questions is 'true' is that you are asking "Why can't I have Windows Feature (x)." LinuxIsNotWindows. You just need to change your mindset a little.