Chances are if you straddle other people will straddle as well and then whatever EV you gave up will come back to you and even out.
I don't thinks I've eve played in a casino where more than one player was straddling at the table. Even if you got a second player to straddle, you are not getting back the -EV to even. You give an advantage to 9 other players. If someone else straddles, you gain 1/9th of the advantage.
Straddling will result in bigger pots in which case your skill advantage is multiplied. Inexperienced players tend to make bad decisions in big pots where they are not comfortable.
This is the only advantage to a straddle. You effectively raise the stakes at a table, and those stakes might be more than Timmy McTourist wanted to play. Timmy's poor decisions are going to default to tightening up, and folding more often.
Also when people are having fun they are more likely to rebuy after losing rather than storm off in a huff.
I agree here. However, if someone is straddling, making the table blinds bigger than Timmy McTourist wanted to play for, and you just burned through his initial buy is half the time he expected it to last, while all he got to do was pay for flops then fold. There is no was he is going to donk off more.
The straddle just kills the fun.
I would argue that having fun is always +ev. I am not picking on you but more the generic poker player with headphones who doesn't talk and never straddles cuz its -EV. I think those stereotypical players are not thinking about the other factors at play. Poker is about math but it is also about people who in some sense are your customers.
Again, fun is +ev. This is best done by opening up a conversation at the table. If Timmy McTourist feels like he is playing in his garage, he's not going to leave. He's going to donk, rebuy, donk. His $ per hour cost will be considered the price of an evening full of fun. He wins, even when he's losing.
That's the reason I hate hoodie-and-headphones-guy at the table even more than straddle-guy. Because Hoodie isn't talking. He does nothing to loosen Timmy up or put Timmy at ease.
Straddles are -EV, and kill off the fish.