If this were so, then the price of altcoins would depend not only on the price of Bitcoin, but also on other coins that are now used as a pair on exchanges and exchangers - ethereum, litecoin and others. However, this does not occur with examples of other coins.
The price of altcoins really depends on the price of bitcoin, however this is due to the high level of capitalization of bitcoin, as a result of which bitcoin can have price dominance over other types of cryptocurrency.