Soon-Kian Phang wrote:
I didn't know the usage of katakana for children's names had become common
I don't know about common. Up here in inaka Tohoku, at my junior high and it's feeder schools, both elementary and kindergarten, none of the kids have names written with katakana, and only a few girls (all from the same family) use hiragana.
The "complaint" the some of the older staff have made is that the use of very rare readings is becoming popular, so that they sometimes don't know how to read a kid's name without the furigana.