Unfortunately, it's not the process, as the corn itself which is excluded from most of the paleo/primal diets. Even sweet corn-on-the-cob is an artificially bred product and most modern strains are so far away from their origins that they're completely sterile.
For alternatives, looks like the "Paleo Movie Snacks" thread had some good ideas:
Not Paleo, but I have it as a treat once or twice a month, with plenty of pastured butter!
My research, so far, indicates that the corn grown for popcorn is not GMO.
Definitely not paleo. But I sometimes (couple times a year) have it. I make it the 'old fashioned' way on the stove in a heavy deep sided cast iron pan with a heavy lid with coconut oil. Avoid microwave popcorn, it tastes bad and is laced with chemicals. The lining of the bag contains perfluorooctanoic acid which not only gets on the popcorn but the fumes pollute the air in your house.
Definitely not paleo, but I occasionally have it as a treat as well. I buy organic, non-GMO corn. I pop it the old-fashioned way with coconut oil, and I use lots of pastured butter.
We buy a non GMO brand, pop on the stove top with coconut oil and put on a little butter. Probably not considered Paleo, but a nice treat for Sunday evening when playing Clue or Catan with our kids.
Dragonfly, 90 percent of seeds used for American popcorn is GMO...just FYI...
I have removed all grains from our diet and if I re-introduce any of them I feel bloated and terrible. That being said the fam convinced me to make an exception this sat eve and pop some corn in our air popper for movie night like in our pre-paleo days. Topped it with melted grass-fed butter and salt and waited for the pain and bloat to kick in. But it didn't. I went to bed feeling happy and with a nice flat tummy. My paleo journey has been not to stick to doctrine but to go food by food and see what foods my body is OK with. This experience has given me food for thought. I have always thought of corn to be forbidden but now I'm thinking we'll have to see. Occasionally as a treat I'm thinking it may be no big deal.