It is unreality that altcoins are not tied to the price of BTC, let us assume if one day the price of altcoins have nothing to do with BTC, it may be the end of BTC and the end of the crypto market.
When bad news comes out, it's always causing panic, and people sell one by one natually and i think most of them are newbie.
I think they are not so tied up as before! It's all about the pairs on the market... before Bitcoin was the only pair for many alts, now you can trade alt/stable coin pairs!
Reality is one, crypto is a free market! Anyone can choose to buy or sell at any price... whale or a small-time holder/trader, and according to buy/sell orders of the certain pair you can see the market move!
Someone said a long time ago "do the opposite from what masses do and you will harvest profit all the time"! Don't panic when others do that, use that for your own advantage!