My main reason for using a PC is simple. It's Apple's poor job porting their software to PC's. iTunes for the PC is the most frustrating software I use. Rarely does it connect to an iPhone via WiFi. The settings are not in one place. It fails to load at times and I have to reboot. It gets a 10 out of 10 on the "Cussable Scale."
I have felt the same way about a lot of music and musical device software that was designed for an Apple and then poorly ported to Windows.
I am a music anarchist, and Apple's "ownership" of their software nauseates me, too.
You do not have to have the "best" machine, the "best" software, etc. to make music. You do have to write, write, write. Just the other day I read a list of songs Willie Nelson wrote. There were a whole bunch of them that I had never heard of. Let's say that 5% of what he wrote has "stuck." That's a phenomenal percentage! I bet the songs he wrote that didn't please him could fill up several filing cabinets, too.
If you wanna make it in the music business, you have to realize that it is mostly business that gets you to the goal of "making it." Probably 99.99999% of musicians hate business (except when it's time to get paid). We'd rather be playing. For this reason, you've got to find someone who loves marketing/business as much as you love music. If you do come into some good money, put a huge part of it on a publicist and a business manager. Make sure that they love what they do and would do it for free (but like to get paid just like you with your music :-)
I know plenty of musicians who are KILLER, but they did not have the heart for the business/marketing end of things. They play a lot locally, but never did get discovered.