Take solace, big corp won't let you change your wallpaper away from the approved one with the company logo, precisely so that no one is ever offended. That is the tradeoff.
Maybe the same thing that makes big corp so safe is also what makes it so boring that your friend wants to work in a startup instead.
Maybe startups have so much potential because you're opinionated but otherwise rule-free, so the tradeoff there is that not everybody is compatible with the company culture.
Maybe I'm a white Mormon, and there are millions of us in the USA (more of us than there are Indians, btw) who don't drink either despite the pervasive American drinking culture, and get pressured to drink. all. the. time. But get along better with an office of mostly Indian Muslims because none of us drink or send porno pictures to each other over email, entirely by choice rather than by regulation. And we can do it all in a tiny company with few rules because we have a company culture.
Maybe startup culture needs more Indian (or Mormon...) founders.