I think it's the result of:
- People new to crypto buying the most well known coin
- People wanting a huge profit since a lot of people are buying btc
- Bitcoin maximalists that fail to see that there are crypto better than btc
- The fact that in most cases you can only buy altcoins first buying btc
EDIT: 5. Bitcoin's name
Yup I agree with all your points, especially having to buy bitcoin before alts. Once people can buy alts straight from fiat without paying huge fees that may very well end bitcoin's #1 market cap reign. I followed ya back btw.