[dragonwriter]

> Critics argue that companies shy away from it because they cannot control it.

No, they don't. Critics point out that companies avoid it, and non-critics ascribe this avoidance to "can't control it", which is false, because nothing under a third-party copyright under any non-exclusive license can be controlled by the licensee, but businesses avoiding the GPL don't generally avoid all non-exclusive licenses.

[cyphar]

I think "can't control" refers to sublicensing in this context. People's dislike over copyleft stems from wanting to make software proprietary (or proprietary-friendly through lax licensing). Copyleft removes that control, and the GPL's main strength is that it is so ubiquitous that you cannot practically avoid it (in most cases).

[dTal]

Insofar as companies avoid it, they do so because it constrains their behaviour in some way. Call it what you will; my wording was perhaps sloppy.

For the increasing number of companies that do participate in the GPL ecosystem, they do so because the opportunity cost of not participating outweighs the concomitant behavioural constraints. This produces a strong network effect as GPL software gains contributors, making GPL software more useful.

Wikipedia's anti-censorship strategy is analogous in that the switch to HTTPS raised the opportunity cost of censorship to the loss of the entire Wikipedia "ecosystem", which for many regimes is more severe than the "cost" of not censoring. This too produces a network effect as Wikipedia gains more contributors, thus further increasing its value.