They also anticipate on the price that will go up because the demand will increase due to people that are willing to buy coins before the block halving. I am fairly sure if the price stays around $500 without moving much, the difficulty will still jump with at least 5-10% per difficulty adjustment. These prices are great for miners. If the price goes up even more, then it's even better for them.
You're argument is flawed. You're missing the point that this is the highest level ever difficulty has reached and the biggest ever increase in difficulty. These are not miners "turning on" their mining equipment as you claim. This is brand new capacity joining the network at massive rates. If you mind checking the media you'll see that several miners have made announcements of significant capacity and efficiency increases in the recent past.
You also miss the point that price and difficulty will never be correlated in the short term. If they would even an idiot would make money trading and that is not the case. Speculation is based on appreciating the differences in price and value of an asset and trading accordingly. Hash power / difficulty is one of most, if not the most, important determinants of the value of bitcoins.
I'm guessing you are bullish for 2016?