I didn't say that all of Sukhumvit was a red light district, I specifically said "lower Sukhumvit," certainly the area around sois 2-7, which is ground zero for seediness.

The Thais in these red light districts haven't had bad experiences with "certain" Indians, they have had bad experiences with a disproportionate number of Indians, which causes them to treat all Indian-looking visitors poorly. I'm not saying their behavior is correct, that's just my best explanation for why you were treated poorly.

Also, I had no idea that there were places on Walking Street in Pattaya that were not gogo bars or pick up joints, but I haven't been there in ten years. I encourage any curious readers to do a search for Walking Street Pattaya in google images and you'll get a fair representation of that scene and the clientele.

When you hang out in seedy red light areas, weird things happen, often not in a good way. The treatment you experienced in these areas is probably not representative of how you would be treated in the rest of Thailand.