That point has already been reached.
For most people, Bitcoin mining is not profitable unless you live in a place like Iceland (i.e. with access to cheap, abundant electricity) or you have an already-installed solar panel/wind-mill installation that's already paid for itself and can divert some of that electricity into feeding your ASIC.
Electricity expenses are the single most important fixed cost for miners and, with the current continuous escalation of both hashing power and difficulty, should you buy a machine now you'd never recover your initial inversion unless Bitcoin had another round of 10x increases in prices versus fiat.
Likewise for scrypt-based coins, buying graphic cards and refrigeration equipment is not worth it anymore unless you have access to darned cheap electricity.
That's what happens in a completely free market: since there are no hard or legally mandated barriers to entry (or to exit) profitability for first comers drops very fast due to the continuous improvements in productivity that newcomers are bringing forth. So unless you can keep innovating (as an ASIC producer) or buying new equipment (as a pro-miner) you'll be left behind and become unprofitable.