The reasons PCs outsell the Mac 10-to-1 are numerous, but let's focus on two key issues: choice and price.
All sorts of people need to use personal computers, and they have all sorts of requirements, budgets and experience levels. The PC marketplace offers any imaginable combination of price, service and selection; the Mac marketplace is dictated by Apple. PC users can buy a preconfigured Windows system with no installation needed or build one from scratch. There is a choice!
A mildly experienced PC user willing to install Windows (it takes about 20 minutes) can go for price. Hi-Tech USA sells a fully equipped and assembled 33mHz 486 for $1,400. Windows and a mouse push it to just over $1,500. A discounted, similarly configured Mac IIci sells for $3,700.