The whole crypto will always act as one. It is not because of individual characteristics of each coin but it is because of human behavior. We humans tend to group things together so that in the markets, industries fall and rise together.
Good point from that part as the hole industry was supported by investors and there's always people who will keep bringing new ideas but will also
take part of the original concept. Alts will depend from bitcoin and bitcoin investors will look after alts to bring something good from their investment.
It is true that when the market is going up similar assets have a tendency to move together but this tendency is even greater in the market of cryptocurrencies because as we know a substantial amount of the projects are just copies of bitcoin which means that they are heavily dependent on the behaviour of bitcoin for their progress.
And that is a problem because everything depends on the fate of one single coin and when bitcoin is not doing well then the whole market is not doing well.
Well it is because no other altcoin can keep up or meet what bitcoin can do now so altcoin's behavior and price will really be dependent on what is happening with bitcoin and indeed almost every altcoins is copied or have the same system as bitcoin has so no doubt why altcoins move depend on what move bitcoin has but i think it will not stay that way always, we are innovating and so do altcoins so maybe there will be some innovation that will happen to altcoins that can chage the way it is.