On my opinion I think that, Bitcoin is 100% the most popular crypto because it was made before any other crypto had been developed (in the same way that Bitcoin was developed), if Bitcoin was to come out now it would be tossed aside because there would either be a coin that is more popular than it, and/or coins would have way better technology than Bitcoin and then there would simply be no reason to use Bitcoin. But I agree also on your opinion that, all crypto currencies are the only way to unite people by a common idea. Bitcoin was the first crypto currency so it is more popular. If we do not see the constant evolution of coins and it will be a bubble.