Bitcoin is the most popular crypto currency because it is the first born of all crypto currencies. Its popular because it's price has gone up since it's creation years back.
Bitcoin really became the first cryptocurrency and this allowed this system to take a leading position on the market. Now Bitcoin has a developed infrastructure and it has well-known name like a brand.
Bitcoin and blockchain are not like the company. It does not have anything like infrastructure as you said, because the community of Bitcoin are its miner and its user. Its community do not create by some people, it create by all users of Bitcoin and become a "family" to protect this system.