The Altcoins prices are correlated to BTC price. The prediction of Reddit co-founder is a bit irrealistic. especially when you consider the global cryptocurrencies marketcap. That prediction should be for 2020.
But for some cases, altcoin can be better than bitcoin because as we know, altcoin demand getting greater from time to time.
Let's compare ETH value for example with BTC when it has same ratio with ETH.
I can see uptrend for ETH in this year !
These two can be in rivalry in terms of popularity in the futue as their repective price will deeply influence the market with respect to trading. That's right altcoins demand became greater but not in general, because there were some that doesn't pump its price due to lower demand. Right now ethereum has increased its value due to more trading of eth contract tokens, but it doesn't mean we'll be expecting more for it and definitely the value of eth is always in contrast with the value of bitcoin itself.