Playing the devil's advocate here, why is it OK to pay a developer in India $3000/year when they could command $300,000/year in Silicon Valley?

Also, unless they joined within the last year, the current employees signed contracts obliging them to come to work 5 days a week. If they wish to permanently move to working from home in their pajamas for 5 days a week instead, the company is basically saying "Sure, but that will be a 15% paycut because we feel that makes you less valuable to us". You're welcome to disagree with the company's view, but it's not particularly "unfair" to me.