In a vacuum the straddle is indeed -EV. However, it offers a lot of great things and should be incorporated into your game for the following reasons, which is primarily leveling via table image.
Putting money in utg blind is typically a horrible decision and majority of the time you are just throwing away 2 big blinds and won't even see a flop, many other times you're over playing marginal hands out of position that can lead to kicker issues, overplaying middle pair, etc. This is why straddling is -EV.
However, +EV and -EV can't be looked at in a vacuum. Frankly, if everyone played optimal poker then poker would be predictable, hand reading would be incredibly easy and this is why you need to mix things up and play dumb periodically, especially if you're playing a long session where people are going to get a feeling for what you do. The ABC nits do get paid off, the thing is though that they only get paid off over short sample sizes vs really really bad players who don't care or pick up on the fact that said player that hasn't seen a flop in 4 orbits in a row and is now suddenly opening up big and 4betting preflop.
Basically, if you were playing a single hand, zoom poker style or against very bad players then straddling would be a horrible idea. However, if you're going to sit down at a table with some competent players over several hours you should straddle a few times, even if you just plan on folding your 2 big blinds. The reason why is because people will correspondingly adjust their image of you.
If you straddle and there are no antes then the pot opens up at 250% greater in size (NL 1/2 = $3 opening pot vs $7 pot with straddle) and the money is committed by people that are out of position and blind. This correspondingly makes stealing very tempting as well as forcing everyone to expect the steal and expect any bets will need to be larger than normal. It's this anticipation that you are creating. It puts people off balance, they make leveling decisions rather than card decisions and you can get very good reads on people.
The straddle is never about that single hand, sure you may hit bingo and wake up with KK and someone with QJs 4bets you all in trying to level you, but more likely then not you are donating 2 big blinds into a pot to put everyone else in uncomfortable situations. You will give off a false table image while also gaining valuable information about your opponents.