Yes. I have flown into Quarsazat and returned to UK via Casablanca whilst touring. I have also flown into Casablanca and returned via Marrakech Airport. Dependent on where you are coming from, planning on visiting, then returning to, will dictate your options.

On a buget for example: If you are travelling to Morocco from Europe then check out the cheapest flights availible that you have access to ie: Ryan Air, Atlas Blue etc. Where they land would become the start of your adventure.
Decide where you want to go after you have visited Morocco and see which Airport and which flight company can get you to your onward destination. This becomes the end of your journey.

What you do in the middle ( your adventure in Morocco) will be dictated by the time you want to spend, what you are interested in and how big your buget will stretch. Then plan your journey to accommodate.

I have also purchased Ryan Air "One-way" flights from Luton/London to Marrakech, so I do not have to worry when exactly I have to leave. At a stage when I am ready to return to UK, I simply go onto Ryan Air's website and check dates, giving myself a few days of choices, and see which one is the cheapest then consequently depart on that date.

Hope that helps.