Since the future price of Bitcoin is unknown, at the end of the day you can not really decide if mining is profitable with maths.
I stopped mining when I generated less money than I spent for electricity (the gear had already been paid off). However, back then the exchange rate was maybe 5$. If I had known that it would be 100$ two years later, perhaps I could have mined longer.
What the Bitcoin experiment taught me is that I am not a very good investor... The good part of mining was that I did it for fun, so there wasn't much to lose. The mining rig is now my new gaming computer. So even if I hadn't made any money at all, at least I would have gained a new gaming rig. In that sense it was a good speculation, for me personally (no real downsides but potential upsides).
I felt that by mining I also supported the idea of BitCoin, so it had ideological value for me, too.