It wasn't. Rather, it was simply not talked about mostly because of Edwardian ideals trying to get away from the Victorian ideals (in which such things were somewhat discussed, just in very tight social circles). Also, it wasn't just a "West" issue - it existes in many cultures.

Also, if you look before the 20th century, you'll see that sexuality wasn't repressed at all - it was just meant to be in confines of marriage mostly and many of the medieval and renaissance writings and drawings are just as bad as anything you'd see today.

The problem with the Kinsey Report is that it looked mostly at male prison population which...well, is about the same then as it is today. Not exactly the most reliable of data.