I wouldn't be surprised if racism in the tech industry was more towards Indians.
Unfortunately some people take a fairly legitimate gripe (lack of easy communication) and pre-judge an entire group rather than investigating the skills and attributes of a specific individual.
On the other hand, we would often have people call in who had strong accents, and the tech support agents would often judge the callers as 'dumb'. I earned a reputation of being a genius, not because I was a genius but because I'd actually listen to people and try to understand them (sometimes they were hard to understand) rather than being an asshole to them.
In short - it was very common for people on both ends of the phone to rationalize racisim with a hard to understand accent.
Put someone with a deep southern mountain accent and someone with a Brooklyn accent on the phone and they'll feel at odd with each other. Surveyed afterward, they will both probably feel the other is stupid and didn't understand them on simple things.
I myself remember my first experience with someone at a call center, who I can only assume wasn't in the US. I was calling Network Solutions in high school about a domain registration. The person on the phone I recall as having an Indian accent, which I didn't mind so much, but I did feel at odd with them when I needed to spell my first name (David) out to them using the NATO phonetic alphabet. It just struck me as so incredibly odd at the time that someone would potentially mishear or misspell the name David. However, I quickly realized that it was simply a cultural difference. I myself would probably get a common Indian name like "Sita" wrong. Was that Seeta? Seta? Seata? Site? Its only 4 letters, but I could screw it up for sure. I've since been more understanding of people at support lines.
Just as people often say that racism is ignorance, I do have to feel that this wasn't me being against anyone from India (as I actually knew very few people who maintained much Indian culture, language or accent where I lived at the time), but being ignorant and impatient with what was normal for them vs what was normal for me. Thankfully I learned.
Did you just say "Delta Alpha..." or "D as in Delta, A as in Alpha"?
I can assure you the first one would confuse the hell out of most of the Indians(I am an Indian living in India).
Some of the NATO phonetic alphabets would complicate matters even further - Quebec, Zulu, Yankee. Zulu is a special one, considering Z isn't pronounced "Zee" in India(G is "Gee" and there is no "Zee") - it's called "Zed". So when you say "Zee" as in "Zulu", the support staff is going to have a hard time figuring out what on Earth was that. This is pure speculation - most likely support people undergo some training and they have a basic understanding of western accent and pronunciation.
The safer bet is simply saying the alphabets "Dee a vee eye dee", or better still use short, widely known words as mnemonics "D as in Doll, A as in Ant, V as in Van..."
I often have to resort to phonetic alphabets. Though sometimes it becomes problematic when the mnemonics I come up with confuse the support staff even more:
Me: "Dee..Ummmm Dee as in Dumbledore"
Support Staff: "????"
It was chosen specifically to work through bad communications channels and diverse accents, especially if you use the specific pronunciations required for the words (kay-beck for quebec, etc.).
That's as a caller though, I've never worked in a position that requires me to take calls from the public. I've often been met with pleasant surprise by call-centre staff when I use it to clarify non-obvious spellings, and always request a read-back check.
They understood it well enough, but from my POV I was shocked, because never in my life did I have to spell my first name. I know in the US to always make a clarification of the spelling of my last name.
The normal line I give people in the US when they are looking up my account (perhaps at at bank) is, "My name is David Fisher, with no 'C' in Fisher" (since some spell if Fischer) and that normally does the trick.
You do make a good point however that just because the NATO phonetic alphabet is standard for NATO, doesn't mean it is something understood worldwide, anymore than I'd understand Kanji.
As regards to lunch, many Indians are very selective about eating habits (for religious reasons). That prevents them from eating in meat-'contaminated' areas.
None of this excuses them from socialising however.. But, socialising with people you already know is easier than making new connections. Which is just lazy, IMO.
So don't blame them entirely.
I've never lived out of a city with a population of less than 100,000 so I suspect that the social dynamic might be somewhat different there.