PhoenixRising

And now I must reply to this post and clarify a few points. Arrow's ratings, while having gone down, have hardly been a "disaster," and any decline the show experienced had little to do with Olicity or Laurel's death. Arrow's problems began long before Laurel's death, and stemmed from the writers' failure to adapt Laurel into the story properly as well the lack of a compelling villain storyline after Deathstroke in season 2. The Ra's al Ghul and Damien Darhk storylines were mishandled and stretched the limits of credibility for the show. And it's worth noting that back in season 2 of Arrow, fans were practically clamoring for Laurel's death as her character had been very poorly adapted and was not given an actual story arc, and even worse had been made an annoying and disliked character who often did foolish or illogical things. This had far more to do with the writers not properly adapting Laurel from the page to the screen, and making Sara Lance the more likable Black Canary and Felicity Smoak the more likable love interest. But killing off Laurel was the only recourse the show had left since her character had little to do other than be a sidekick or teammate and was never really given a compelling story arc of her own. Also, Olicity is hardly "loathed" by the majority, as it is the second most popular CW couple after Jughead and Betty on Riverdale... which by the way, is another non-canon couple and the most popular couple on that show, just in case you needed another example of "going against comic canon and succeeding."

Now, as for The Flash, it has never stuck with "main comic canon elements." Iris West on the show has very little in common with the character from the comics. The Team Flash dynamic at STAR Labs was never part of The Flash comic(STAR Labs was actually based in Metropolis), and Barry being partnered with Caitlin, Cisco, and Harrison Wells is also not part of comic canon. The only canonical elements from the comics are the ones the show uses the least. Barry's partnership with Wally West as Kid Flash was a big part of the comics, but Wally has been mostly a side character or recurring character on the show and has often been absent for the majority of episodes. And Barry and Iris did not grow up together in the comics with Barry as an adopted sibling. It's also true that Iris did in fact die in the comics, only to later be revealed has having been a woman from the future. Not much about the show has followed comic book canon.

And you're incorrect when you say that "Berlanti would never make the same mistake twice" because he already made it with Iris. Just as with Laurel Lance on Arrow, Iris West was poorly adapted to the show, has little or no story arc of her own, and does not have much in the way of compelling or interesting character progression. Her main role has been mostly "token girlfriend" or "damsel in distress," but her relevance to the show has been very limited. Iris spent the majority of season one completely separate from Barry's storyline at STAR Labs while she was with Eddie Thawne. Iris' role as newspaper reporter is never a factor on the show and she is rarely if ever seen at her job, and her going from coffee house barista to newspaper reporter halfway through season one is highly unrealistic. Iris has little to no relevance at STAR Labs(something she herself noted in the Invasion crossover) as she has no scientific or medical training and contributes very little other than simplistic dialogue that could have been given to anyone. And her relationship with Barry is based mostly on off-screen backstory the audience never gets to see instead of being developed slowly and gradually as the story progresses. Barry doesn't fall in love with Iris, he's just in love with her because the writers say he is from the first episode, and that's not really very interesting. That's basically the same mistake Berlanti made with Oliver and Laurel on Arrow, establishing their entire relationship as pre-Lian Yu backstory rather than something the audience got to see progress naturally, like Olicity.

Now, the ones to blame for this are the writers for copying the format of the original Flash TV show from 1990 where STAR Labs was the main storyline and Barry and Christina McGee were the main couple, and where Iris West imply did not fit in. The writers of the new series attempted to insert Iris into this format without properly thinking through exactly what her role would be or how she would fit in. They assumed that just being Iris West would be enough, but it isn't. Three seasons into the series and Iris still serves little or no purpose to the show's narrative, has no story arc of her own, and does not fit into the dynamic of Team Flash. It's also worth noting the TV critics have lambasted the show for its steady decline in quality, with its convoluted continuity resulting from way too much time travel, its tired repetition of the "evil speedster" storyline, complete with surprise plot twist, and how the show continues to stretch credibility with Barry constantly making bad, stupid decisions that negatively affect everyone around him, making him seem totally irresponsible. The majority of fans and critics still say that the show's first season is still the best one, and that season focused on the trio of Barry, Caitlin, and Cisco, who are the true heart and soul of the show, while Iris was mostly out of the loop. And don't go thinking that Iris West is some universally loved character. There are just as many fans who are tired of the WestAllen drama(or lack thereof) and would prefer The Flash to be The Flash and not "The WestAllen Show." Berlanti may choose to stick with Barry/Iris for "obligation's" sake over storytelling and narrative necessity, but considering how far the show has dipped in quality over the last two seasons since doing so, I doubt the show will ever be as good as it once was in season one, nor will it ever achieve the greatness it could've had.