I completely agree that flex queue is ranked. I'd even dare say that flex is as ranked as solo/duo. The difference between Flex and solo/duo is the fact that you can play as 1, 2, 3 or 5 people in flex, the more premades in your team, the more premades in the enemy team.
Riot mentioned that they made the flex queue for a more team-based queue, so you could make all kinds of specific champ-related teams, not like solo Q. Let's say you played Solo Q. most of your team would also be Solo Q. Therefore, everybody would just play whatever they were comfortable at, whether it was a late game champ, an early game champ that can stomp, or a champion that wasn't even in the meta.
In flex queue, however, you could tell your team "Okay guys, I'm going Vayne, a hyper carry with low range and therefore, weak early. Can we have a team around that?" and your team can respond with either "Sure, I'll play Lee, and early game champ with high burst to camp bot" or "I'll play something tanky that can peel for you late game, or maybe even engage". or maybe a 3rd option, making a full wombo-combo team, filled with Vel'koz, Jarvan, Orianna, Miss Fortune and Gnar, but as you can see, to make a wombo-combo, u'd have to get to at least mid-game without screwing up hard. You can't expect that from solo Q's.
I'm taking Solo Q and Flex Q just as serious, and I've reached Plat 4 on Flex, Plat 3 on Solo/Duo ( I just demoted from P2, sadly 
).
Flex queue has been out for a decent time now, people should be in the rank they deserve, whether they should be in that elo thanks to their skill level, or for not taking Flex Q as serious as Solo/Duo Q. Just gonna point out that Riot is even giving end-of-season rewards for both queues, and a special reward if you reach gold+ in both of them. I was never a fan of ranked teams, honestly, they were not quite appealing to me, nor my friends. If we ever played ranked team, it was for the sake of playing with each other during a LAN, yet for the sake of it being competitive, we didn't resort to normal games, and we'd probably stop after finishing our first 10 games, (usually reaching bronze-silver, which we didn't care about at that time, for as said, we didn't take it serious, we'd usually disband the team right after).
Conclusion:
I'm quite sad about the community's thoughts and feelings for Flex Q. I've seen lots of trolls in Flex Q for not taking it serious, especially if they were autofilled support. It didn't hit specifically me too hard, since I can play all lanes (except ADC, practicing on that), maining support and mid. (Rito pls fix ranked system, people who main just 1 champ r rekking me hard cuz I don't have a champ to spam the hell off of..)
I bet some people in bronze-low silver in solo Q could easily reach high silver-gold in flex if they had a team to coordinate with, instead, they are stuck with the mentality of "Nobody is going to carry, I have to carry, both myself, and my team." that's the lovely thing about flex, and I really do think that flex has extremely good potential for the future if everybody took it seriously. There are lots of friendly people in flex btw, wish I could give all of them an honor after the game, but new honor system won't allow me 
I hope other people share my opinion and thoughts, sorry for making the comment so long, but I've harvested and kept these feelings and thoughts for my own for so long, and finally found a post that somewhat agrees with me.
