It is impossible for exhanges to know the full etory of all of the 10s of thousands of crypto projects that have launched. The best they can do is set up certain reasonable criteria and parameters for the project to meet, and then allow the free market to pick winners and losers, and warn each other of potential scam projects.

When $DOGE first launched, it was done as a joke. Some may have considered that a "scam" by some estimates. But over time the joke started to take itself more seriously, and is now a top 20 project.

Who can say for certain where the ultimate value lies in each different protocol or project. Consumers need to take more active responsibility in evaluating projects, not less.