just to rephrase the fact (above),
that ethereum mining costs only near $15
(almost 1900% profit margin now, compared to bitcoin only ~50%, even at current prices) and that price will also be much nearer to $15 again:
Miners have choice and care about their coins/networks. They represent the true calm future value/price bottom. The growth is a continues trend line , much rather linar (than parabolic or anything) just like the real growth of amount of transactions. (Some miners who rush into Ethereum temporarily onlyfor the extra profit may switch over to the next profitable coin again, once ethereum calms down and prices match up again. But others stay mining what they like on a long term, with a modest profit margin and cant be bothered by bubbles just staying for some days. )