Need opinions regarding my user management library after hard reject

I’ve been a web dev for 13 years, my expertise is PHP, and I’ve been working for some high profile Western companies in the past (think Paypal). After working for more than a month, for about eight hours every day, I submitted my library to Codecanyon, only to get an email five days later, saying it’s a hard reject. Now, the only reason I can think of is the aesthetics, since I am not a professional UI developer. Please take a look and give me your opinion. Is it really bad? I’ve run it through other people I know from real live before I released it here, and they all said the UI looks nice.

DEMO: http://nauthentication.recgr.com/

Source code excerpt: http://pastebin.com/rnNmQt4U

Thank you