One of my India friend has applied for a B1/B2 visa for multiple times and did not get approved, even though he had already traveled to quite a lot countries.
I also got rejected a B1/B2 visa for 3 times (I'm holding China passport), and I finally flew and moved to U.S. after my company sponsored me a H1B visa.
The B1/B2 visa is truly the hardest visa to get for most third world people.