Alright, I feel like I'm going to slay a sacred cow here. 

" Show, don't tell." should be changed to " Show and tell." 

Yes, it's the number one golden rule of writing. It's what every English Lit teacher tells us in middle or high school whenever we get a creative writing assessment. I think the problem right now, barring first-time fanfiction writers who robotically write out every single line, is too much showing and not enough telling. In fact, I believe this rule is the ultimate source of purple prose that has plagued an healthy amount of literature. Summary and brevity can have its own dramatic effect as well and serves an essential role. There should be a balance between both. Obviously, this will vary depending on what type of genre you want to write and so forth but it's not something that you should follow dearly to your heart.