A lot people are working on Bitcoin full time, but most of them no longer visit this forum. While those who are here helping out with technical questions, in my view, do so for more knowledge. However, from the look of people's activity here, it's certain that many members of this forum have got different purposes, work, business and Target in Bitcoin or outside Bitcoin. Therefore, those that work full time in Bitcoin only depend on Bitcoin market to earn. While others diversify their investments.
Many people will also say: You bought Bitcoin, put it there, forget about it, you dont need to work. It sounds ridiculous.
This advice made the early adopters so much profits that's why they keep telling people to follow same hodl method.