There are many sorts of difficult.
Making money online is not physically taxing. It doesn't require a genius level IQ or a grad-school degree. But it does require effort and above all patience. For some people, this might mean that earning money online is easier than working a traditional job. For others, it might seem far harder than just pounding the pavement and finding someone to hire them.
I firmly believe that the opportunity is there to make money online. If I didn't, I wouldn't be here learning more about it. But I think that opportunity is limited, not by geographic location or physical stamina or educational credential or any of the factors that limit offline opportunities, but by the willingness to push through frustration, build an income bit by bit, and draw upon several skillsets and avenues to do so. Earning money online directly contradicts just about every lesson we learn from traditional employment, where you get all your income from a single source, get paid for your time rather than your productivity, and earn a set wage from your first minute on the job. And it takes a certain sort of personality to embrace and profit from those differences rather than getting discouraged after a week or a month and throwing in the towel.