It's a free market. As soon as bitcoin started having problems in 2013, the alt market exploded.

You can try to force bitcoin to be the "One True Coin" by ensuring it's not on the exchanges etc - but you can only succeed if you have a Soviet style system where they ban everything else. In a free market, if people want an alt, and your exchange has banned it, they'll just go to another exchange, or start an exchange themselves to list their alt.

I get why some bitcoiners are alarmed about how many alts there are. But people are buying them because they offer stuff bitcoin doesn't.