It's because of the hardwater Bengaluru gets.
Once I went for my engineering in Bangalore used to face scalp dryness and hairfall very often.
I am not saying it's because of the bad water as people who are born and brought up in Bengaluru are used to the hard water, so they won't find such issues. But for people who are used to soft water and moved to this city for education/work purposes this will be common.
P.S: I am from Karnataka only, so please don't begin with your "Go back to where you came from" bullshit.
Respect the city as it's state capital but every city has it's own drawbacks and it's better people acknowledge it rather than defending it.