For me those both situations only make market better for investors to just catch some coins at good prices for trade or just hodl next months.
True but also consider the fact that bitcoin is main source of money for buying an altcoin. If bitcoin price drops then the value of the altcoin drops too. Those who want to buy that altcoin need to be careful at what price they are buying otherwise they will not be able catch when they drop.
Perhaps, this mostly refers to little-known and unpopular altcoins at such exchanges as Yobit and their likes. Major altcoins like ETC, LTC, etc are all traded against fiat as well, and it actually remains to be seen where's more volume. Apart from that, the majority of people who trade these coins are well aware of their dollar price and their cross-rates.