How Companies Think About IT

I think I’m going to get back to the 80/20 or 90/10 Paradox here, but bear with me.
I’m not sure I understand how companies think about IT anymore. Most of the companies I work with will spend dollars easily on keeping hardware working, but they won’t spend much thought at all on their software.
Let’s put this in perspective. Occasionally, I have a client buy a new computer from BigBoxRetailer and then call me. “You mean it doesn’t include Microsoft Office? I paid $500 for this computer, and it doesn’t include anything to write a letter.”
“Oh, yes,” I tell them, “There’s WordPad if you want to use that. I don’t think you’ll like it, thought.”
I learned a long time ago that it’s important to say what is just obvious to me. Some people don’t realize that Windows is…well…basically useless on its own. It’s like having an iPhone with no apps. You can make calls and do some basic things, but the things that people expect to be able to do with their computers cost extra.
So here’s what puzzles me: computers (meaning Windows + hardware in most cases) are basically useless without software. Yet people replace their computers every 2-3 years without thinking about it and their software almost never. The last statistic I saw suggested that businesses look at new software of the kind that operates their business only ONCE every FIFTEEN years. Asked why, they say it’s too expensive.
That’s like buying a car, keeping the oil changed, and keeping the tires balanced, but letting it sit in the driveway because gas is too expensive.
It just makes no sense to me.