They call it bubble because they compare it to the stockmarket, most of them are not aware that cryptos are nothing like that. Its the idea behind it and a deflationary system. The will always believe its a bubble, because they dont have the right perspective. I dont believe its the right question to ask. is it a bubble or is it not? The right question to ask is. Does the system prevail? Is there a use or function for it? Does it have longterm value?