Are you seriously taking issue with my use of the word combat for a situation in which at least one side is attacking the other? I don't know how you think combat could happen without creatures attacking each other.
Because it's the rules. Initiative is a part of combat, but it happens before anyone can possibly attack anyone else. It simply isn't possible for it to happen after someone attacks, because the very instant someone so much as thinks about attacking, initiative is rolled and that person could be going last, having never attacked. Again, it's simply not possible to roll initiative AFTER someone attacks. Even in a surprise round, initiative is rolled before a single person attacks.
What are they surprised by if not surprise attacks? Correct me if I'm wrong, but the way I'm imagining what you're describing is two parties are sneaking along, each undetected by the other, until they come upon each other at an intersection. At that point in time, they both notice each other, so by the surprise rules, no one is surprised if combat breaks out. Am I missing something here?
They are surprised by the appearance of the other side. I have walked around a corner and been surprised by a squirrel that I didn't know was there and run up a nearby tree. I have rounded a corner and been surprised by a TV sitting on the sidewalk that I wasn't expecting to be in my path. Are you really going to argue that the TV was attacking me?
And no, if both are sneaking, then both can be surprised by RAW as neither side noticed the threat before it was upon them. Initiative is rolled and they do nothing in surprise, then attacks begin in round 2.
I don’t think the word typical explains how participants “in a battle” “engage in combat” by standing around dumbfounded that they’ve managed to bump into someone else in a dungeon. Has it occurred to you that combat is typically a clash between two sides because sometimes it’s a clash between three or more sides? Or would you rather maintain your assertion that sometimes combat isn't a clash between any sides, at which point I think we've departed significantly from the meaning of the word combat?
The word typical simply means how combats typically work. The atypical portion is not defined, so is as likely to include what I described as it is to include more than two sides.
Well, they give two examples of directly opposed efforts in the contest section, another two in the section on melee attacks in the form of grapple and shove attacks, and of course the most common example is in the hiding rules, but there aren't any examples or mention in the book of efforts that are considered indirectly opposed. I honestly don't think it's worth distinguishing them as a separate category.
Whether or not you think it's worth distinguishing as a separate category, it is in fact a separate category. You cannot determine what direct opposition is, without knowing what indirect opposition is. Opposition is always one or the other, and only one uses the contest rules.
Contests are also defined in the "Contests in Combat" sidebar as representing challenges that pit one participants prowess against that of another. In initiative, each participant's Dexterity, which represents prowess in reacting quickly among other things, is pitted against the Dexterity of his/her opponents.
You're stretching things here, but regardless, initiative is not direct opposition and never will be.
Both of your statements are false. Initiative is how we find out whether I'm successful in swinging my sword before you cast your spell, so it most certainly is initiative, and initiative most certainly is an ability check.
No, initiative isn't finding out whether you are successful in swinging your sword before I cast the spell. Do you know why? Because after you roll initiative, you might change your mind and push me, or grapple me, or run away, or a number of other things. Winning initiative doesn't lock you into an action, while you are locked into your action as soon as a contest begins.
There's no indication from his tweet that his motive has anything to do with combat sometimes involving more than two participants or the degree of directness of the opposition represented by initiative.
Going by his tweet, all we know is that initiative is not a contest. Period. Nothing of his motives are given.