That's one way of doing it. But any current coin provides at least some profitability to it. So, even if you decide to mine DOGE or LTC which we aren't seeing at the top of the profitability charts lately will provide at least some profit. And it could be considered serious cash depending on the size of your farm, and what price it is when you sell.
td,dr: My point is that profit, even serious profit, doesn't have to come ONLY from mining new coins as they get added to exchanges.
I should have broken my statement up with and/or instead of and.