>>106250473
I think different people have different reasons but there's a general consensus that it's bad.
Girls don't do it because a guy they decide to ditch can call them from hundreds of numbers and blocking won't help.
Criminals don't do it because police can track your location, the accuracy is like 1m. It's like that in all countries.
If you give your number to a crackhead, he can tell it to services than lend money with high percentages and tell them that you are his relative. Then they will call you and tell you that that guy doesn't give the money back and that you have to tell him to do it. Don't know much about it but I saw the news from Russia that the gangster from that service threw molotov to apartment of the crackhead and burnt the toddler. Maybe everyone heard similar stories and doesn't want to deal with them.
I don't give my number because I'm a freetard and i like privacy.
It's extremely hard to get a phone number of university professor, especially the ones from radio physics faculty, probably they know something. They only communicate with email.