The Arrowverse all started in 2012 with, well, Arrow, and has grown exponentially over the years, creating a number of sequel and spin off shows, as well as a plethora of characters.
Of course there are the clear, well written main characters of Oliver Queen, Barry Allen, Kara Danvers, or Sara Lance, but these heroes are bolstered up by an ever increasing roster of supporting characters.
Most of these characters range from anywhere between beloved people like Arrow's John Diggle - bodyguard to the Green Arrow, who is loved so much that he has fan theories devoted to him becoming a Green Lantern - to more one note characters like The Flash's Ronnie Raymond, who was fine enough, but no one really batted an eye after his off screen death between seasons one and two.
Then there are of course a few of these supporting cast members who make viewers want to claw their eyes out every time they come on screen. Whenever the showrunners devote an entire storyline to some of these lesser characters, it can be enough to make some fans switch the episode straight off...
10. Curtis Holt
When Curtis Holt was first introduced in Arrow's fourth season, he was measuring up to be an excellent addition to the team on the tech side of things. Not that Arrow needs anymore Batman comparisons, but if Overwatch was Oliver's Oracle, Holt could have been his Lucius Fox, providing the vigilante billionaire with new gadgets to try out week to week.
But no, Curtis was dead set on becoming Mr Terrific.
It's not the fact that it couldn't have worked, it's just the fact that it didn't. Curtis never came off anywhere near as physically capable as the others on the team, even against Rene, who was just some guy in a hockey mask. Furthermore, when Curtis was out in the field, not only did he look out of place and unconvincing, but he was always whinging.
Curtis never shuts up about how difficult things are for him. He wants to be a vigilante, then proceeds to complain about being a vigilante. When things go south between him and his partner, Paul, he blames it all on the vigilantism, which is fair, but here's the thing - he wanted to be one!
All of the things that Curtis complains about in his annoying hyperactive way are of his own making. When he leaves the team, he could have patched things up with Paul, but he never even tries. Instead, he works for ARGUS, and then guess what? He finds new things to whinge about.