I don't think you can criticise others for wasting, say, $4 a day unless you also have no frivolous purchases.
Most people have some sort of money leak, and the key difference, in my mind, is whether the money leak is voluntary and controlled, or involuntary/uncontrolled.
E.g. if someone really likes a morning soy chai latte and is willing to spend $4 on it every day, and can afford it, great.
If someone does it out of caffeine addiction/compulsion, and doesn't want to do it but doesn't know how to stop, not great.
Same goes for any other expense. The only criteria I use to judge expenses are -
1) Do I get proper utility out of it, relative to other expenses and the opportunity cost of the money?
2) Is it an expense that I can control today, and into the future?
You could criticise people for spending money on church, pets, make-up, or other "frivolous" expenses or you could accept that people have different priorities.