Nothing else was as profitable (and ETH profitability had already dropped), and depending on your costs switching won't be worth it for many. Even for those who

Nothing else was as profitable (and ETH profitability had already dropped), and depending on your costs switching won't be worth it for many. Even for those who is the other mineable currencies are much smaller and will likely be oversaturated with just a fraction of the hashpower which was going into ETH.