Why do Tamil people don't allow unmarried people to wish for new married couples?

I'm basically from Kanyakumari, now settled in Bangalore, running my own business. My office manager is very close to me; we're friends and we have known each other for a long time. I frequently visit his home, and his family members know me well. I was diagnosed with cancer when I was 27 and lost the structure of the left side of my face. When my mom started looking for a bride for me, every proposal ended in rejection. By the time I turned 35, I told her to stop searching because I couldn't able to handle those rejections. This guy's family knows all of this very well why I didn't get married. In South Tamil Nadu weddings, there is a tradition where we hold a mango leaf in both hands and rotate around the couple three times as a way of blessing them. I was standing in line to do that when this guy mother pulled me aside and told me I should not do that. **I felt so dark and confused.** If a girl or boy didn't get married, they should not wish new married couples? I'm confused, so just posting here to get the tamil nadu people's opinion on this.