I agree with the OP, if you actually read the first line where they state some people can't do it and that's alright. I think there will be a lot of people who have money they could save up, but not necessarily blow it, but certainly spend it when not really not needed. But as mentioned there is a balance between being a spend thrift and profligate.
There's a thing going on in this thread where £3,000 saved up is either a pittance or a lot of money, which makes no sense, same goes for the people trying to make it work out that spending £600 saved up on an emergency is a bad thing, because it means you don't have the £600 anymore?!? I'd love to see the mental gymnastics in action to an explain how that's not worse than going into £600 of credit card debt for the same emergency?
I used to be in a lot of debt, and have clawed my way out over the years, and now in a phase of trying to save for things and not spend unnecessarily on credit cards, and buy everything on debit card instead. I send money into a savings account each month, and some of the things I'm saving for I'm only saving small amounts, two of them are holidays I hope to go on in about 10/12 years time, so yes over time the small amounts will add up.
And people saying cutting back on things to save for a house deposit isn't worth it, that's literally what me and my partner did, and that should be like the bare minimum you have to do unless you're loaded, we're living in an age of instant gratification, where people want the newest and fanciest things instantly, in total disregard of any negatives, and that's how so many people are in debt problems nowadays.