That is a part of the very core of gambling, the desire to play more and inability to resist it, without that, it wouldn't even be gambling in general.. Regarding the exact physiological and psychological reasons, You can google it, IMO almost anyone can get addicted to gambling if they started it.

Currently, The majority of users are not like they used to be i.e "people with excessive technical knowledge who understand even the deep technical aspects of bitcoin", The majority now can be considered ordinary citizens..
Regarding the ability to use bitcoin, it doesn't take anything more than having a PC and internet connections (plus money, to buy bitcoins).

Most people dream of having an online job, not needing to do services in the real world and having no boss or the like, Even in bitcoin that is the case, However making a life of bitcoin is difficult because it's either focusing on earning BTC through small tasks or through trading BTC to USD, both of which aren't consistent and hard to rely on as a source of income.