First of all people need to learn difference between perspective coin, shitcoin and scam. Shitcoin and scam are similar but again different. So here we come to whitepapers and people behind project. You need to understand crypto and to see potential in idea. If it's bad or copy paste idea, simply don't bother with that. To get that skill you need some knowledge and experience.
Yes they're both similar almost.
Let's put it into term that shitcoin scammed those long-term holders of the said tokens through exit scams. I believe there are numerous project that did that because all their aim was to get quick $$$ then disappear into thin air.
Many new projects aren't for long term that's why many are claiming that almost 90+% of alts aren't gonna survive the winter cold dumps.