The continuous flow of it's market and money that is coming in to bitcoin makes it to become always to be the number 1. And it is the first crypto currency that was introduce, those next alt coins that came out eventually got the idea of it. This is the most popular coin that is going to make it always the number #1.
Bitcoin as of the moment is $19,613,123,089 while the number 1 altcoin which is ether is 2nd with $3,931,294,37,
that is a huge disparity and we can clearly see bitcoin is the number 1 and it can beat all altcoins combined.
Well that just show that bitcoin is the best. It is being trusted by a lot of people, investor and businessmen. And I'm comfortable that bitcoin will remain it's spot for the rest of our lives. Being the original and source of the alt coins, we can also see that it keeps on growing day by day. Once the problems about the blocks will be solved, this will make it more stable.
I think you are right. Even if an altcoin was better in some regards only a small number of specialists would understand that, and regular people would prefer to use Bitcoin anyway. If Bitcoin will avoid major problems in the future, and hopefully it will, it will be #1 for a long long time. if not always.
Look how long it takes to convince people that Bitcoin is in many regards better than USD. That's because people are hesitant to accept anything new however good it was. Same will be happening with any altcoin no matter how many advantages the altcoin has.