The main reason for that is dowry and extremely bad treatment meted to women in India. Most people prefer to not have girls at all given these scenarios. Imagine having to spend money on your daughters education, tending to physical safety and then only to find the boy's family asking for big money gifts during marriage. And not just that, in most common cases the demand for gifts just keep coming infinitely even after marriage. The demands are insane of course- Asking for large quantities of gold, real estate, or just plain hard cash, cars combined with a demand for lavishly marriage party are a common place here in India.
Some people have absolutely no shame and sense of self esteem and resolve themselves to this kind of begging to get money. This includes people from all over India, regardless of caste, religion, color, regional, linguistic belongings.
This whole thing promotes a culture for a madness to have male children.
I am assuming marriage among people of same gender especially men is going to be a common place in India only a couple of decades from now.
>> Should men who don't have or can't find a normal relationship
Such men should actively work towards a society that doesn't kill girls before birth and after wards. If they can't may be they should suffer and live in the society they built.