Why can't IP67 waterproof phone look more advanced?

I've known that IP67 is the highest waterproof level for cell phones but i didn't get through many of this kind before.Until today ,i broused casually online and found (HAIER) W718J - a IP67 waterproof phone, which seems to be the most attractive feature of itself. www.tinydeal.com/haier-w718j-px1r4ix-p-109226.html

Well,this appeals to me actually but other specifications r just so-so( like 4.0" screen size, 512MB RAM, 4GB ROM,800 x 480 pixels screen resolution .... ) So i really have a doubt ,after assosiating with other waterproof phones i once saw, why coundn't they be more advanced and professional ? I can't stand seeing ordinary phone with waterproof function ,i want a highly-equipped one! Or maybe some hidden reason behind this?