What is with the obsession with ADCs?

Despite the meta constantly changing and swinging around back and forth, the role of ADCs as vital factors and the center of attention has stayed consistent, firmly planted in the meta. Why? On a competitive level I see exactly why they would opt for focusing so much on one person. Having a person who can dish out insane DPS and melt their team is vital to winning, and since monster faceroll champs like Yi, Trynd, and Kat are easily countered and played around in LCS level play, and autoattacks are the most reliable source of damage in the game (You can't dodge em, can't spellshield em, can't cleanse em), it only makes sense for ADCs to become incredibly effective and vital to a team comp. Furthermore, Assassins are not very good right now in competitive play because of the sheer amount of crowd control available to players and the reflexes and coordination that these pros have allow them to instantly lockdown an assassin before he can do his job, and at that point the assassin has failed. But all of this dissolves once you get to lower ELOs.

• Faceroll champs like Yi, Trynd, and Kat run rampant with nobody stopping to think "Hmm, maybe full damage isn't the best way to build Warwick"
• Nobody runs summoner spells like cleanse or times things like spellshield correctly, and people are terrible at dodging skillshots (This is balanced out by the fact they are also terrible at HITTING skillshots)
• Players at this rank are generally far worse at positioning, which is punished by far most severely on ADCs.
• Lack of communication and more widely varied skill levels (Bronze-Silver skill levels vary widely, from players who are obviously climbing and have a general understanding of the game, to people who ask for blue buff on Yasuo.) leads to teammates being unreliable, which means that the constant care and peeling that ADCs in high levels get just isn't there. This is mostly an ADC problem because most facerolly champions have ways to survive and peel for themselves ( Yasuo windwall and shield, Fiora ult and parry, Tryndamere ult, Yi's entire fucking kit)
• Assassins completely destroy Marksmen at this level because their teammates are, as said above, unreliable. I'm not saying as an ADC in low ELO you should blame your team, not at all. I'm saying the teamwork and communication just isn't there.

So this brings up the question of why even bother with ADCs if you can just send one of these facerolly champions bot lane, along with a support, and play things out exactly the same but with a champion with a more self-reliant playstyle, that can do well without his team having godlike peeling....

If you have any opinions on this I'd love to hear them, because obviously I don't know best, and this isn't meant to be a "STOP USING ADCS" thread, just spurring some discussion concerning the current meta of the game and how unchanging the ADC role is....

EDIT: I'd definetly give a free pass to Kalista and Jinx though, as they are very powerful champions regardless of being ADCs or not.