That's correct and...maybe never was even the case.
With 855 currencies and 215 assets shown on coinmarketcap and more announced almost everyday...bittrex and others pick who they want to list...it's that simple. They're bombarded  every day with requests.

Xspec is not a new project having launched November of 2016.
It's way past it's early early stages, has been gaining new users quickly and moving forward to a bright future.

Although it's possible bittrex takes notice....there are many other excellent exchanges around the world.