For me bitcoin is just an extra income because when you don't have a skill to give then your source of income is limited . But when you have much skills to give I think it is possible to earn a decent amount of bitcoin monthly, And I think when some years passed by and bitcoin is widely used and known then more opportunities will also come.
I agree, if you have skills to offer you can earn good amount but like me i only earn extra money and not enough to sustain the needs of my family for everyday. of course i also dream to be rich with bitcoin maybe in the future if i go full time.