So, this makes it pretty tough for small startups or 1 person projects to acquire users via ads, since they need to do it on the cheap, which isn't really possible. It's one of the few startup related expenses that has gotten more expensive over time, rather than less.
And why has it gotten more expensive? I believe it is because there is a bubble in this space, but not what the original article is claiming. The bubble is from the boat loads of investment capital in online startups. They take their 100m round and have no issue paying $5 per user, losing money with every one.
Companies that need to be revenue positive (or just don't want to waste money) can't compete with the high ad prices that this creates, which I think leads to a lot of hostility towards the whole space.
I believe another reason for the negativity is all the fraud related to online ads. It's hard to not be negative when there are so many accounts coming out about just how much of the paid advertising traffic isn't even real.