I understand, and you're not alone. Many are cautious of altcoins. However, not all altcoins are scams. Ethereum and Ripple provide new technology and ideals to crypto. I agree about the sentiment-driven market; Bitcoin is everyone's big brother. Everyone moves when it does. But why? Is it sentiment or more?
Imagine if every coin had sentiments. Would the market be stable or chaotic? Bitcoin is powerful while being decentralized. I advise you to diversify, investigate, and never put all your eggs in one basket, even if its flashy and called Bitcoin.
To be on more safer one, never expects the very best from the market because they tend to make frustrated and disappointed. The market is volatile, this minute we watching the bullish candles pumping and next minutes we experienced a bearish candles that would changed our face to frowned ones. Bitcoin have aides some of these top investors in the space, making them top back to full position with there current stands in the market. From day one it has always been bitcoin, though I've invested in other alternative projects but I keep 100% concentration on bitcoin.
diversification is still advisable even in this market so as not to avoid total liquidation of your assets when one of your coins go down without a warning.