Someone obviously wont earn any profit if he starts trading without looking at the history of a coin because as you mentioned there are a lot of scam coins these days in altcoin markets so they just disappear after some investments of people.
so don't invest your money blindly here.
Well that is already a lesson for me either because I have experienced that before. That is why I am just going to buy the coins that has going to have the potential even though they are going to fluctuate slower that is going to be fine with me. As long as there are movement to price still you are earning it is better to earn slower rather than never.
You have a point, buying potential altcoin could be risky but there are some altcoin had the potential to pump sooner. Thats why its really important to research about the coin you would like to buy so that you would have idea oon that certain coin not just purchasing it away and doesnt even care about anything.