They were talking about mining, and from the previous sentences, i believe they were referring to how hard it is to get the block reward (25BTC in 2015) since it's pretty much a "race" between those with a lot of resources (mining equipment).
I think the same! Earning here means mining! And we all know that mining is not at all easy these days! The kind of equipment and investment it requires, can only be arranged by the deep pocket individuals. So in this sense, earning bitcoin is hard, really really hard!
During initial days of bitcoin, it was easy to mine by individuals! But not anymore! So the benefit of bitcoin can only be reaped by some selected individuals right at the moment. Late entrants are still struggling to get their share of pie!