Micro doesn't make or break every game. But, when it comes to it, Macro is full of Micro skills. Evenly skilled Micro teams do have to fight it out in Macro; there is no way around that. And, teams that have less Micro but more Macro than the other team often win. But, the argument must be made that when your Renekton or Trundle feeds their Riven, who in turn has excellent Micro, it's practically game over. Although it is entirely possible that you could stop the Riven; however, that means dragging out your bot laners and maybe even your jungler to do it. Really, yes, League of Legends is all about the Macro. That's what wins pro play most of the time; Macro decisions made that push the game in one team's favor. But, that being said, most players in LoL are Bronze/Silver (like me). The main reason these people are ranked so low is because their Micro isn't as good as other opponents; when Micro is even, however, Macro decides the game. No offense to Bronzies or Silvers (which I am one of), but our Macro kinda sucks. That's why, in lower levels of play, Micro usually decides the game, while in higher levels of play, Macro almost always decides who wins. But, the reason that Micro has, and in my opinion usually will, determined so many lower ranked (or unranked) games is because in order to contribute to the Macro you at least have to know what you're doing. And, even when you do, you have to be somewhat relevant to help (barring tanks or champs with a lot of cc; those are almost always helpful). And, in order to keep relevancy in your game, you have to be able to farm decently, or get kills, or at least stay a little bit behind your lane opponent. Although Macro could very well save your team against a snowballing lane opponent, if Macro is about even (like it is usually across ranks, but most prominently in lower ranks [spoiler: at lower levels of play, you probably have bad macro, and so will your opponents in most cases]). When Macro is even, Micro will decide the game.
Yes, that's essentially what they did for the Fire/Ice 1v1's. It's a test of isolated skills, which is why I'd suggest a test of skills being a 1 vs 1 match, a 3 vs 3 match, and a 5 vs 5 match, because the combination of all three matches shows everything you really know about LoL, Micro and Macro.
But, you have some really good points. I'm glad you took the time to type out a well-thought out response. Macro does usually win the game, but in scenarios when Macro is about even, it's Micro that decides the game. And, when Micro is about even, it's Macro that decides the game. When both are even, Macro takes a larger role in the game then Micro, simply because Summoner's Rift 5v5 is and always will be a team-centered game. But, at the same time, Micro still plays a role in the game's outcome.
Overall, I think my original point was that 1v1 is still a relatively good measurement of personal skill. Sure, it doesn't test Macro, and it isn't the best test of personal skill, but it's better than seeing who is better against bots, and it's certainly a legitimate measure of certain skills.
But, that's my opinion. I mean no offense to Bronzies and Silvers, but the truth is that we are at that rank because it's an accurate assessment of our skills. Sure, right out of placements you might be lower than you should be because of that one teammate that throws the game and feeds. That's my story in a nutshell. But, given about 50 or so ranked games afterwards, you should be right around where you really belong. There's always room for improvement, yes, and that's the point of playing more games; to get better and climb the ranks. And some bronze/silver opinions are very valid; they are people who have a good understanding of the game but rank lower because of their Micro or Macro.
Have a nice day!