Why the hell can't I have seperate words as my last name on my PSN account?

My last name happens to consist of 3 words. This is nothing uncommon.

Just now I went to update my profile and account information on my PSN account, and when I entered my last name, it told me "There are no spaces or special symbols allowed".

So now, I had to write my last name together as one word and it looks like shit (and wrong).

What the hell Sony?