Given that the article makes a case that Netflix and cable companies started by exploiting grey areas in legal contracts, it's clear that they're talking about competition that broadly. The fact is, weird grey areas or loopholes in contracts (basically everything that undermines "protection" against competition) is an opening for competition.
The logical conclusion is that much of contract law is in the way of competition. But the point is that whether we think competition is good or bad or contract law should exist or not or be strict or whatever, the companies in this case are not following the Golden Rule.
Contracts were intended to block things like Cable TV or Netflix, but they came into existence by finding loopholes in those contracts. The argument is that their exploitation of the loopholes added real value, invented new services etc.
The arguments about competition here are anti-protectionist. They basically say that since we recognize that Netflix added value, we not only should be glad that they found the contract loopholes, we should probably eliminate all such protectionist contracts.
The argument about regulation in this case is that we don't necessarily need regulations to protect digital rights because it's trivial enough to technically enable them as long as we don't prohibit the rights legally. Take away the legal enforcement of DRM, and DRM becomes irrelevant for technical reasons. Thus, no digital bill of rights is needed.
It's not my argument (I'm not sure), but it's logically consistent.
In short: legal protection of DRM enables companies to have profit and power and avoid the threat from new types of companies, services, and innovation that would otherwise happen and would be in the public interest. The public isn't only interested in Netflix alternatives but in all the world of innovative developments that would be possible if we removed the protections of Netflix's business model (even if it doesn't protect Netflix as a player in that model).
Really short: it's about competition between types of businesses or between business models, not competition within a business model.
It's about cable competing with airwaves; about radio competing with live concerts; about books competing with priests, etc. not about competition between different books etc.