Rant hat trick! Yay!
So, my biggest issue with solo queue always has been and always will be communication.
Let's assume that's you're going for a League qualifier to get yourself up to the next shiny badge. You're current score is 2 wins, 2 losses. You're team is mostly decided except for you and one other guy. Both of you want the same role but the only other role open is one you're comfortable with just not *amazing* with and, although you don't know it, the only other role is open is one that the other guy doesn't play at all because they're nowhere near comfortable enough with the mechanics of that role.
What do you do?
We'll assume you have pick order over them for this.
If nothing was said in chat and you lock in the role you wanted and the other guy gets stuck playing his absolute worst role which we'll assume is top-lane for this. He picks Nasus or something that's good at being passive and defensive early on. Well, Riven who is now 2 levels above him just dove him with her ultimate and he died a third time. Everyone else does meh but no one really comes out ahead except Riven for either team.
What could've been done to prevent that? Sure, Nasus could've played further back early on but we'll say the second death was to a jungle gank so he had more to worry about. He isn't comfortable enough with the mechanics of top-lane to know when to farm and when to sit at tower or how easily it can snowball so are you just gonna flame and blame him all game? What good does that do? They already know they didn't do well, you telling them that isn't going to help.
What could've been done to prevent that is communicating with them. Ask them if they're comfortable with the other role that you know you can play at least okay.
Now, some people will think that they're just gonna say they're bad at the only open role because they want their first pick for role. That'll happen, yes, but most of the time you would be surprised how cooperative people can be when given the chance to be.
Now let's try that again. You're in-game as Mundo against Riven. Not your greatest matchup early on but you can sit back and chuck cleavers at the creeps for a little while. The other guy is doing okay in his role, you may have been able to do better, maybe not. Everything in the game is nice and even for about 50 minutes until the enemy team manage to pull off a really good fight and win the game.
Is it anyone's fault? Yea, someone probably made a mistake but it's also entirely possible that losing would've happened either way.
Not everything has a happy ending, some times you just have to take what's dealt to you and do your best. This doesn't mean you could've done better if you were replacing them or you could've done better than them doing whatever. You're not trying to be better than them, you're trying be better than yourself.
For the longest time, I never tried exceptionally hard in ranked. I just kinda played whatever champion I felt like at the time and didn't really care if I won or lost. I ended up mid silver because of that and clamped my League Points harder than you'd think a Silver player possibly could.
At the end of Season 3, I decided to try winning. I played my best champions or whoever I could get my hands on that was ridiculously strong at the time if I knew how to play them and I carried myself out of Silver II, into Silver I, and then got myself to Gold V after one failed promotion series before grinding up to promos again and winning them. This was all with a huge LP clamp until the lost promo when my LP gains went from 5-8 to 15-19.
It's now Pre-Season 4 and I've managed to pull two divisions in two days, getting from Gold V to Gold III with minimal effort by playing champions I'm comfortable with and communicating with my team. Not everyone is cooperative, it's true, but not everyone refuses to cooperate. Some people want to win just as badly as you do and they're going to give it their all the same way you should.
Just be open with your team. My personal preference is to let them know what my top two choices are for role and let them know which role I play the worst(prefer mid/adc, can't jungle too well).
If you end up getting the role you're not great with, tough luck, maybe next time. That shouldn't stop you from giving it your all.
I swear I'm not Canadian.