Bitcoin is not a scam.
Let us suppose a while that bitcoin is a scam then what happens with these following thing

Bitcoin circulating suplly is about 16,858,762 (Wikipedia)

Total bitcoin worth goes to 1.2 trillion USD at the end of 2018 as expert says.

Number of bitcoin users to reach 200 million by 2024 as expert says.
 
If you thinks about theses figure ,you will get your answer.