If you are looking at profitability in fiat value, then it's quite self-explanatory. Bear market is already taking effect and in the coming days/weeks/months. Mining most alts will not yield any nice profit to keep you running.

It's the period of time when one has to be ready to mine and wait for 2-3 years for a bull run to be able to sell off the stash at good price.

You bet? 

I am more than confident the bear market already started. For this Bull run, the all-time high was 68K in Nov last year. The funny thing about bear markets is that you don't realize that they are on until it's too late