Your points are very valid, especially when it comes to buying coins because they are cheap, or FOMO because everyone is talking about them. Honestly, if investors took some time and actually looked at the use cases of the particular coin they were looking to invest their time and money in - they'd understand whether or not that investment is right for them.

For example, for long term holds I like to invest in commercial-focused coins, so their primary userbase is businesses who care more about the bottom line than the story that consumers are gravitating towards. Thats why I looked more into Stellar and Ripple than other coins.