That's because you guys are ill-informed. Don't know where you got the idea that saving would lead you to riches but it doesn't work that way, nor was it portrayed to work that way in the first place. What you mistake savings for is investment, where you put your money into work instead of slaving for it on your daily 9-5. With investment, you get the guaranteed benefit of earning more than what your salary grade provides, with all the liberties the market could provide you, which in turn allow some of the people who ventured into investments to earn millions and find riches.
On the other hand, savings, as the name implies, is meant to "save" your money for the sake of something else. Instead of splurging it all into booze and bitches you keep a portion of your money for yourself as emergency funds, will the emergency funds make you rich? No! What it will do to you is make sure you don't die of poverty when you do get sick.
I hope this analogy shed a light on this massive misconception against savings. You're not supposed to get rich off of saving your money, if that's the case then we'd have a lot of scrooge mcducks in here already, you're only saving because you have to prepare for a massive, often unexpected expenditure in the future. Nothing more, nothing less.
Left for me, I think it's the people that doesn't have an investment plan or what to invest on that would just save their money in fiat currency, well like you said it's not a bad idea, but you benefit more when you invest your fiat on a good business or asset that would yield good profits, there are lots of things people could invest on, like, Gold, Real Estate, buying of shares from top rising companies or even invest in bitcoin, just like the OP said, saving won't make one become very wealthy cause the fiat you're saving won't appreciate but would rather remain stagnant or even depreciate when the country is facing inflation or economic crisis, but if you make good investment on the right asset you could make double profits of your savings in future.
Also I think the idea of saving is mostly among the poor and some middle class people, rich people barely save their fiat, but rather use it to make investments in business and assets, for one to be wealthy you ought to quit saving the fiat you have, maybe in the bank or any anywhere but think of a good invest plan that would help grow your money and yield you profit in future, in conclusion to your statement, my advise to people is that saving might be a bad idea but investing your savings to get more profits is best.