Bitcoin demand was always high to investors than altcoin and it will be always. It's a simple fact that when market start going down traders sold their altcoin to increase their btc. The point you made in your topic is really important. Many people don't think details like that but when you start calculating very details you'll find how many btc everyday you are losing because of altcoin trading. But it also true that crypto trading doesn't run in one specific way. You also have to choose several way to survive here.