Everyone replying here seems to be quoting "business reasons" which seem very English-centric. Try to talk to a Japanese or Korean person about their "business reasons".
I am suffering the opposite problem. My name has 36+ letters and I live in Japan, where the average full name has "3-4 characters" (Kanji) so they tend to be safe and allow for 10-15 characters, if I'm lucky maybe even 10 for given and 10 for family names (20 in total), where I don't have to totally murder my name and just need to amputate it.
I am suffering the opposite problem. My name has 36+ letters and I live in Japan, where the average full name has "3-4 characters" (Kanji) so they tend to be safe and allow for 10-15 characters, if I'm lucky maybe even 10 for given and 10 for family names (20 in total), where I don't have to totally murder my name and just need to amputate it.