Bitcoin can help poor countries
Nope. Bitcoin can only help certain individuals, and not whole countries.
I know many friends from poor countries making a living from earning Bitcoin online
Can you at least tell us what your "many" friends do to earn money? Are they by any chance participating in signature campaigns?
that job can do by following campaign.
Signature campaigns are a great thing, but the spamming got so worse, that some staff members are even considering to completey remove signature campaigns if the level of spam doesn't decrease significantly. Let's assume that happens, how will your "many" friends then earn their money through Bitcoin?