Strange, I used to play lots (sometimes upwards of 40 games in a day) and never noticed those things. Maybe it’s because I wasn’t looking for an external reason for my results?
The trends I did notice were totally on me. E.g. I tended to do worse late at night. Was it because people who play at that time of night are bad and were holding me back (I’ve read this a lot on the forums)? Hell no! I was just getting too drunk by that time to play at my normal level.
Very few are unwinnable.
Unwinnable with non-meta heroes, cause enemies too stronk, cause they have a cheater is typical mood for lower tiers.
Because people are very bad at Maths, statistics and objective assessments.
1st it is elementary to understand it’s mathematically impossible for the majority to lose a majority of match. When one team lose, another win. For 6 losers there are 6 winners.
Further only a minority is Bronze, so everyone else has to win some times.
I could go on… but you get the picture.
And yet this is a very common if not a major behavior in various area of life.
It is much harder to say “I suck” instead of “they all suck”.
i experience this every other season. and typically lose 350 to 800 sr in one streak as a result and then have to climb back up to 3600 where games are easier to fill-flex and not need you to 1v6
They say the games are unwinable for them. Not ALL games but after u win a few lose once or twice…then come back the next day and suddenly u cant win a match at all and it feels like ur skill dosent matter cuz u seem to be being put vs a team of defrans when ur a nobody. Its not like u went from being gold to GM in one day. But yet it feels like the matchmaker thinks u did. That is what most r talking about when they say the games are unwinable.
To the argument of “defran would win those” yes they would…but defran has either way to much adderall in him…he was born playing shooter games…or has praticed for a HUGE amounts of time on his game play. And i or the normal player has none of those…yes they can gain that but u cant get that good over night nor can u get that good in one season (aside from O D ing on adderall…not recommended) so yes those games would be unwinnable for the normal player. 
Why? I can’t answer that because you are absolutely exaggerating. You can’t get serious answers if you aren’t serious.
People complain by saying their teammates are trash, people say they have throwers, and, like you said in one of your recent posts, said everyone in bronze is a smurf. So what’s exaggerated when everything I said is posted in this forum daily?
3 dps 4 dps or 5 dps. Maybe throwers and smurfs. take your pick.