I thought the same thing 12 months ago. History so far has proven us wrong.
Actually no, history has proven you (I'd say us except that I didn't make a prediction a year ago) right. Difficulty has not doubled every month. In fact it is now increasing by only about 60% per month.
Difficulty *will* double every month until the most efficient ASIC that is possible to create is only marginally profitable.
That would require the rate of increase in difficulty to
increase, an unlikely (but certainly plausible) prediction.
meanwhile our singles will be obsolete in June. (making less bitcoins than what it costs to mine in electricity)
Well, June maybe, that's 5 months out, not 3. And there will always be people with cheaper (all the way down to free) electricity, so they will never be fully unprofitable, just profitable to a smaller and smaller market (which affects resale value). I agree they don't have much value at that point.
Efficiency will determine who will win the long term Bitcoin mining game.
True. "Long term" is a weasel word though. Nobody knows what that means in the real world.