As they break or wear out over the years, I'm slowly replacing them with top-quality stuff. However, I would NOT have wanted to "buy it for life" when I was first starting out (even if I could've afforded it), because I didn't know my own long-term needs well enough to predict which tools I'd actually need and use often, and what features I'd want in them.
If you buy good quality stuff that's actually the wrong stuff for your needs ("why do I even own this band saw that I never use?"), it doesn't matter how good the quality is -- it's still wasteful. So I'd say there can be a time and place for the cheapest possible thing -- and hey, my $5 yard sale circular saw is still going strong after all these years, even if it makes a burning smell....
Impulsive or not, humans are bad at estimating. The purpose of explicit shopping lists and cash only budgeting is to, first, cap spending to a predetermined amount, making a budget much easier to adhere to, and second, eliminate the temptation to cheat.
Does everyone need these tools to help enforce discipline? Maybe not. But given the average amount of savings and debt out there, I'm gonna guess most can benefit from any help they can get.
In essence, your argument is "people should just be smarter". Evidence shows that kind of simplistic, idealistic approach just doesn't work.
It's good to have a shopping list and to be conscious of your wealth/income. However in my opinion the best tool is have a set of principles.
Thinking only about money will often fail you. It's better to think: Given my requirements what is the most cost effective product? You probably don't want to waste time having to fix bad quality items, or going to work with a dirty shirt because your detergent is worthless. Or buying a cheap thing to realize that it was crap and having to buy the expensive product later on anyways(after having lost the money you put on the cheap thing).
On some products, like tools or a car, you should ask yourself: Will this product ever let me down? How long will it last? A lifetime? Keep in mind that pricey products can be good deals too.
On commodity goods spend less, on everything else spend smarter.