Oh boy
The only time it'd be 100% your fault is if you are better then your opponent skill wise and still lose. If people are of even skill or your opponent is better then anything below a +0 MU isn't going to go well for Robin on average. .
Just to clarify, are you saying that if your opponent has more skill than you it is not 100% your fault that you lost?
I'm not sure I'm willing to accept "vulnerable to this character's infinite" as "oh that match isn't so bad, no reason to change characters at least."
Being able to be 0-to-deathed off a jab sounds like about as good a reason as I'll ever get to not use Robin against Fox.
First off, a lot of characters get "0-deathed" off of Fox jab. Also, I have yet to get hit by a fox's "jab infinite". Yes, I have gotten jabbed 3-4 times into dsmash, but that happens to a lot of characters. You cannot be mad that Fox has a few kill confirms off 2-3 quick moves considering he does not have a kill-throw. Next, the fox MU is pretty simple. You get ~20% off wind jab and edge-guarding fox is either throw a thunder spell off stage or arcfire the ledge to force him to fire fox, then just trade LSDair into his fire fox.
You're going to have to explain to me how the Shiek matchup is not pretty bad for Robin
And I mean it as a genuine question. I'm well aware that I do not qualify as a good Robin or a good Smasher in general and that my losses are entirely my fault (or sometimes partly due to lag). And despite any frustrated grumblings I may occasionally have with Robin, I'll main her till the end. I just have a hard time seeing how the Shiek matchup is only -1.
I spent a good amount of time working on this MU to try and learn it. I had previously given up hope as well, but now I understand a few things that help tremendously. So much that I currently think the MU is 45-55 in Sheik's favor. Here's a few general tips:
-NEVER Arcfire in Neutral, and rarely otherwise. The only "OK" time is when Sheik is below the stage, where you can Arcfire the ledge.
-LSFair, LSUair, and Jab are your best friends. They are huge, disjointed, do good damage, kill, and have almost no end-lag. Hit about 4 times with jab or a simple 2 hit combo and then you can kill sheik. Sheik needs to hit you like 20+ times.
-This is the one MU where you charge Arcthunder and then pretend you are a rush-down character aka Marth (I actually find it pretty funny that someone mentioned somewhere that Robin is unable to rush someone down, but this MU's success is based purely on the fact that you CAN).
-NEVER Airdodge, DI and mash jump out of throws unless you KNOW they have to go for uair/fair, and even then don't always airdodge.
-You can trade with needles with elthunder or arcthunder depending on the distance, Sheik actually has lot of end-lag on fully charged needles.
-Something that I'm working on is using LSDair to catch Sheik's 2-frame ledge-grab. If I could master this, this MU would be in Robin's favor.
-This MU definitely takes practice. I spent about 2-3 hours grinding it out to learn everything, and then probably another 5 hours of playing different good Sheiks before I was confident.
-I think I posted a video example and some other tips earlier on in this thread, you should check it out.
Just as an aside, NEVER use a bronze sword aerial if you can Levin sword.
I guess it depends on how one defines 'doable.' No one in here is arguing that Robin has an advantage against high tiers, most going with a disadvantage and some closer to even. 40-60 matchups in my opinion are doable. (Maybe it's because I mained a low tier in Brawl.) The difference between a 30-70 matchup is real though. I wouldn't deem it impossible, but it would be enough to make me switch to another character.
I don't really think Robin's matchups are down to a science yet though - which is likely why everyone has a wide range of opinions when it comes to matchups. This includes not only Robins, but other players as well - since Robin is so underutilized, not many know how to fully exploit Robin's weaknesses.
Regardless of where Robin falls into the tier list, or what constitutes a 'doable' match, having a clear goal for Smash is a good idea. Feeling frustrated at Robin's faults, or overwhelmed by certain matchups, is a pretty good indicator to at least try a secondary - if not find a new main.
I am arguing that Robin has good MUs against high tiers though. In fact, the high tiers I think Robin does well against are (as in I would recommend someone switch to Robin if they were comfortable with him/her if they have trouble with these MUs):
-Falcon
-Ness
-Luigi
-Sheik (relatively to the rest of the cast)
-Yoshi
Those that I did not list are either even, or slight disadvantage. As an example, I think Robin's worst MUs are:
-Pikachu
-Brawler (probably the worst, but hopefully no more customs)
-ROB
-Lucario
-Diddy Kong (yes post patch)
These "bad" MUs could also just be my inexperience though. If I was able to practice these and learn them, they might be pretty good. I feel like Robin has the perfect kit for being able to adjust to any MU. Which is actually why I started an excel sheet that has notes and MU statistics for every character.
There are other things I want to say, but I'll leave it for another time.