1) Most companies are not institutionally comfortable with remote working, to say nothing of remote working internationally.
2) There exist pervasive skill gaps between talented engineers available to work at $150k per year and talented engineers available to work for $12k per year. I respect that many people wished this was not the case.
3) Many investors in the Valley, whose opinions are quite relevant given that one cannot self-fund employee salaries, are of the opinion that outsourcing development work suggests a tech company which will never achieve the path to $100 million in revenue followed by a $N billion valuation, which is what their business model counsels them to search for. They would point out "I cannot think of a single company whose product was not produced in-house in history which achieved that" and they would not be far from wrong.
4) Managing outsourced development is a skill, and its a skill that most companies and individuals suck at, and do not particularly wish to become great at.
5) It is the widespread perception in the American tech industry that BPO companies produce software whose quality is abominable and that the process of dealing with them is pathological, as evidenced by the fact that only companies which institutionally hate software and software people are willing to work with BPO companies. Many in the American tech industry do not hate software or software people, and thus would have a very high bar to be convinced to use a BPO company.