Most of them are, but some coins that people call "scam" are just projects made by dreamers who wanted to join the crypto hype but somehow failed to make the coin useful, not really scams, just a failed business project, exactly like happened in the old dot-com bubble.
I don't believe that all of the altcoins are scam. Some of are authentic that helps individual grow financially. But there are some altcoins just want to ruin the business and wanted to cheat in order for them to be on top. Awareness is better than cure. Investors must be meticulous enough to pick the right coin for them.