I agree about the skimping on your health comment, but beyond that I can't buy much of this.
Sometimes it makes sense to pay someone to do chores for you. For example, when we moved into our current house, the yard had been neglected for about a decade: Bushes as tall as the house, etc. It took a crew of landscapers two days to tear out and clean up -- I'd still be working on it, if I'd done it myself. Of course, I couldn't do it myself because I don't own a bush hog and the other tools they used. However, once that was done, I spent a couple half-days replanting new items. I think I chose correctly which chores to "hire out" and which to do myself.
To use their examples, whether you should fix that leaky faucet or not really depends upon the difficulty of the specific repair and your own skill set.
As for not investing in activities that make you happy, if I understand the author correctly, two possibilities exist: Spend on activities (and she mentions the spa) OR sit home in misery. So tonight our plans are a dinner at home, some TV, then reading -- I'm doomed to misery because none of those are "cost" activities?
Quality also is something that should be measured on a sliding scale. Sometimes you need to buy the best (i.e., everyday work shoes); other times the cheaper options are fine (i.e., church shoes you know will be worn only occasionally, and mostly while you're sitting down). I have good quality dishes to put on my table /through the dishwasher every night, but if we go camping I'm buying cheap quality paper plates. I wouldn't buy a cheap roof to protect my house, but I won't spend on the expensive toilet paper. The list could go on; sometimes quality matters, other times it doesn't.
Finally, buying fixer-uppers can be a mistake -- if you never do the work and the item just sits and sits; however, if you enjoy fixing things and actually finish the project, it's a great choice. In fact, that could be an activity that brings enjoyment to your life.