Well, in this case it's because SFIE isn't running seriously enough or regularly enough to warrant that. Good shoes are a good investment, but not this month, or next. We're paying off debt and there isn't $250 in the budget right now for that (or, this month, even $60-70). Could we trim and save up? Yes.
But not next month, because we have furloughs at the end of this month, affecting next month's paychecks. Fortunately only 1 unpaid day, but still - that's an unpaid day. There may be more furloughs and there will be lay-offs. While I don't think we will be caught by that, you never know.
Financial health is taking the priority right now over physical health when it comes to extras.
And on a related note - that is one reason people don't eat as well as they might. I'm not saying you have to pay a lot of money to eat well, but produce is not cheap, especially if you buy organic. Dried pasta and a jar of spaghetti sauce costs less than $4, and we can both eat at least 2 meals from that. Or we can buy a pound and a half of apples.
I'm not saying that there aren't ways to do it - there are of course. Buying in season, buying frozen or canned, choosing less processed foods, using coupons and watching for specials. Just that it doesn't surprise me that a lot of people rely on fast foods over preparing their own. You can get full for $2 (of hideously unhealthy nasty garbage, yes), which is less than the cons uent ingredients for a salad.