Re: Is it true that 99% of all airdrops are shitcoins of bad projects ?
From my own experience I can tell from all the airdrops that I know the top projects were only: Vite, Ontlogy, Dfinity. All others were shitcoins 
Vite, Ontlogy, Dfinity. Sorry, I dont know about the three projects you mentioned. Have they ever airdropped? The well-known airdrops I know about bitcointalk are DeepOnion and semux. For other airdrops I don't know much about.
The current airdrop is really bad. I don't know why there are so many people who are passionate about airdrops every day. In my opinion, the airdrop is dead.
Regardless, it is true that probably more than 90% of airdrop are shitcoins. They have no value and just a spam token. They do it either to get a list of email for their marketing offers to give them bulks of leads to offer to their client. I seldom participate in airdrop since it is often a waste of time.