Me? I do have a day job and I consider bitcoin as my side job. I don't want to lose that another source of income just because bitcoin is awesome.
Doing both the things in always good, it will multiply your income which can be helpful in future, only depending on bitcoin is not recommended as the future of bitcoin in unpredictable.
Yes indulging on those two is very good you can earn two income with that and just treat bitcoin as side income because we dont know what might happen for bitcoin in future. And for quiting job to do full time in bitcoin i think its very bad idea but if you earn big and have a company involves in bitcoin well why not.
To start a company we need some huge investment, but its not a bad idea I guess, but at a moment I think bitcoin is good only as a passive income and the primary income.
Like you say it needs a big investment and with companies the first 2/3 years are all about investing and investing.
yeah, for starting any company we will have to make sure that in the first year we will not get any profit from it, but the first year is of the year of investment, Ihave saw a number of people who start a good business and they do not wait for the establish of the company and sooner exact on that year they finish everything, saying that the business was unprofitable.