All other Pow coins are invalid, because if people’s attention shifts from bitcoin to other coins, the price of bitcoin increases, preventing people from investing in other coins, because they make more profit with bitcoin
This argument doesn't even make sense. If people dump bitcoin for altcoins, then the price of bitcoin decreases, it does not increase.
Financial bubbles only form when the price deviates significantly from intrinsic value, and then they burst.
What's your definition of "intrinsic value"? How's Bitcoin not having that? And who defines what's the "intrinsic value" to something? To name value to a product, you need another product to use as exchange rate, preferably a currency. Therefore, the value of Bitcoin is determined by what others are willing to exchange for it, whether in the form of products, assets, or currencies.