No, because the main altcoins and bitcoin are rising and falling at the same time, so it's pointless.
Yes when the price of bitcoin increases then altcoins price also increases but there are some altcoins which do not increase much but take care of that. But sometimes it happens that some altcoins decrease much lower and you lose a high amount and even in bitcoin you get a lower amount of bitcoin when you sell that altcoin so for the better security bitcoin is more suggested.