Is there any real reason why charm packs and jelly rolls are cut with pinked edges? Is it to prevent fraying? Is it okay to cut them with straight edges?

Some are pinked and some aren't. There is no reason why you can't cut them straight.

I was once on my way to a job interview and stopped at The City Quilter. The had a sale and they had one jelly roll of Kona solids left for $10.00. Of course, I had to have it, and it couldn't wait until after the interview, because I knew it would not be there. So, I walked all over the store holding it against my chest while I killed some time. Of course, dressed for an interview in NY, I was all in black. I walk out of the store after paying, no one said a word. I got to the building where the interview was being held and sure enough, I had all this tiny lint allover m chest. Luckily the security guard had a lint roller with him and I was saved. Otherwise it would have been bad from the start. I didn't get the job, maybe I should have kept them on as a lucky charm. All of this to say I prefer straight edges.

Sometimes I think the "real" reason they pink the edges is because it makes it harder to tell if the fabric was cut on the grain corrcetly

I think it's to minimize fraying and long threads hanging all over the place.

I dislike pinked edges.

Yes, it's to minimize fraying. I buy a lot of pre-cuts and I cannot imagine in
what shape they would get here (all the way from the US) if the edges were
not pinked. So, for me it's a good thing. :D

Considering that these pre-cuts get shipped several times before they get into the quilter's sewing room, it definitely helps prevent fraying. I know with the Moda precuts, they are cut in Korea, shipped to the Moda warehouse in Dallas, then to me, then to you. They can really take a beating with all that traveling and no telling how many times they get handled in between especailly if they are on a shelf in a LQS. If you cut them yourself, by all means cut them straight if that's what you prefer.

they are cut with pinking shears to keep them from raveling...
manufacturers really can not win no matter how hard they try. they cut pre-cuts with straight edges, sell a few and people complain...they ravel, they are not a consistant size. i washed them they frayed horribly now my 2 1/2" strips are only 2"....
so, they started pinking the edges...now they don't fray anymore but the complaints sure didn't end. now people complain about that pinked edge.
well, they aren't raveling apart anymore...and i agree with the manufacturers...sure wish someone would just accept what is.

Can't remember the manufacturer, but I've bought a few charm packs cut with what I would describe as "mini" pinked edges - no fraying, but not so much lint.

I have bought precuts with regular pinked edges, small pinked edges, and straight eges. I like the pinked edges because they don't fray. I leave them on and have no problem. I sew a 1/4" from the tips.