Why are the hiking journal coats randomized?

That's just the way the Devs decided to do them. Makes it more of a challenge when completing collections. Originally all coats collections were randomised. There are still only relatively few we can choose.

It's to make it more of a challenge for collectors. Some people try to collect all four and having it be random makes it a little trickier. In some of the older coats (Bewitched Pumpkin for example), there were even different rarities where some coats would be more common than others, making them more or less valuable depending on which you got.

In fact having said that I'm not sure if I'm confusing coats and companions. Are any of the coats able to be chosen? Its very late and I cant seem to decide . Think I'll give up and go to bed.

I'm curious, which special coats do let you choose? It seems most don't

Not sure if it counts but you can choose the Vintage Apple coat you get

Parade Apples and Vintage Apples do, I don't think there are any others.

There was a "special 5th element" item (separate from the regular 5th element) a while ago that allowed you to choose your element coat.

The only other coat that let's you choose the one you want is the OW's Apple and that allows you to choose any that has been created

From what I'm hearing and already know, looks like only apples of any kind let you choose what coat you want