The number of developing countries engaging or — or seriously threatening to engage in — compulsory licensing is a tiny minority (the most obvious examples being Brazil, Thailand, and India). The vast majority of developing countries lack the economic power to be able to produce credible threats of such licensing.

To the best of my knowledge, most commentators on the subject agree that Pharma stays away from selling their products in developing countries because those countries cannot afford the biologics at the prices Pharma wants to sell them at. Indeed, this is what gives rise to the compulsory licensing phenomenon you discuss, which means that the latter is more an effect of the overall problem than a cause of Pharma’s choice not to sell drugs in developing countries.

The most succinct way of referring to this problem is the 10-90 gap, in which 90% of the world’s pharmaceuticals are produced for 10% of the world’s population. Obviously, there is significant disagreement on the normative implications of this issue — whether Pharma ought to be selling medications at substantially reduced prices in developing countries — but the primary reason they don’t do so is not because of uncertain patent protections, but because they cannot capture the rents they are seeking in developing countries (or, if you prefer, because they cannot earn a return on their investment).