Some do give it thought. I would rather not have some of my medications in carry on as it may raise eyebrows if searched. It's not illegal but its one less thing I have to worry about.
And
@mrsterryn mentioned what if luggage goes missing.
What if the carryon goes missing? What if someone goes through the carry on?
Important medication (xanax, prednisolone, strong pain killer) is in jacket pocket.
Actually come to think of it prednisolone could be illegal in Thailand which is why it's in with the Lasix.