Hmm. May depend on the settings of your freezer. My thought is that if you pull out two brands at the same time: one is scoopable and one is not? Well my guess would be that the scoopable one might have more air in it and less 'stuff.' My bet is that Bluebell is harder to scoop, right? And maybe the other brand scoops more easily? Maybe b/c Bluebell is a higher quality? I have no idea.
As you try new flavors - check out my favorite. HEB makes a "Strawberries and Cream" sherbet/vanilla blend. Sold in the quarts by the other sherbet. It's wonderful. Scoops easily. Not sure if that's good or bad!
ADDED: My first job was Baskin Robbins. (Thanks a lot, L.. I'm thinking about ice cream sundae's now!). Anyway - the French Vanilla and Chocolate Fudge were always the hardest to scoop. I am not sure why ...... they were in the same freezer as all the others. But omg so hard to scoop. We dreaded when people asked for a hand-packed quart of that stuff.