Analogy should be to the Moore's law, not to price variations.

Are the cpu speeds that we enjoy today a bubble? Shall we go back to using 80386's?

If you're saying the current bitcoin price is a bubble. That may very well be. But don't mix the two issues.

Of course if the bitcoin price is a bubble, and if it crashes, AS A CONSEQUENCE OF THIS, the miners may turn off their mining equipment.  But that doesn't mean the bitcoin network hashing power is a bubble.