We are all delusional. Now, since bitcoin is in the dumps and most people are losing money actually keeping them running we start to call them our heaters in the winter time in the US. It's like we make up excuses to keep them running when we all know an efficient heating system in a house is much better hear then a few electrical spot heaters around making tons of noise.
It's called rationalization.
(also known as making excuses) is a defense mechanism in which controversial behaviors or feelings are justified and explained in a seemingly rational or logical manner to avoid the true explanation, and are made consciously tolerable or even admirable and superior by plausible means.
Basically you keep telling yourself you're "supporting the network!" or "they make great space heaters and make a few BTC cents also!" or "BTC price will spike to the moon in a couple months, just you wait!"
We all know these aren't true, but disregard my stance on the overall mining scene.
I still love seeing these rigs! Lots of great hobby miners in the community, besides the plateauing of profitability.