I'm a bit afraid that the dev team made their cash and are not so much in business to develope the GUI.
I mean i could do this with java in 2 days. I dont unterstand whats their problem here...they have had now 2 years.
Another problem is that people get used to something. Look like whatsapp or facebook. They are used to use Bitcoin. As long that dealers on DN doesnt give discount its hard to make the people switch to XMR. Moreover the volatility atm is not so good for the coin. Dealers could loose 15% in 2 days. Thats not less.
But still, XMR is superior from every view. Only the people around/behind it are sometimes the problem.
So solve this:
GUI
Make XMR to a prefered currency
Alphabay did its job, now its on the people.