People buy lottery ticket all the time, thats total fine, spending $5 here and there for fun. But if you mortgage your house to buy lottery tickets you are crazy.
Same thing with bitcoin. Spend a few grand for chuckle is fine, chances are you wont see your money again. Heck I would pick up a few bitcoins too when it drops below $100.
if you think these two are the same thing then
you are the idiot!
of course there is no argument that investing your whole life savings in bitcoin is a terrible idea but it is nothing like buying a lottery ticket. it is simply because of chances.
when you buy a lottery ticket first of all you have no way of speculating whether you will win or not and second you have a minuscule chance of winning.
on the other hand when you invest in bitcoin you do have a way of speculating whether you will make a profit (win) or not and also your chances are not at all small.