Easy only if you have the same skill and experience as those people. You can never just become a dev without having years of experience and learning. 10BTC surely is easy if you have really really good skills and you know where to work. As you get more skilled, the number of lucrative opportunities increases. 10BTC per month might not even be considered as "lucrative" to these people as they can make much more than that if they work for a company.

But for us that only have mediocre to little skill, signature campaign is already lucrative most especially if you're from a third world country. First world country people will not spend time posting here to get a dollar or two. They will be doing trading, or even startup their own bitcoin-related companies just because they can afford to do so.