The problem isn't just antags. As someone who plays security a lot, I see the issue as a cycle. Antag goes in deciding to roleplay and play High RP. Someone decides to disregard RP and rush the andag and robust them. Antags fear this might happen again or happen to them. Security decides not to do that. Next round, antags act either super cautiously or super aggressively out of fear of validhunters coming in and fucking up their day because "lul valids", And either delays round, causing people to want to hunt out antags out of boredom, or goes in fucking guns ablazing, causing people to want to validhunt to avoid being killed. Move onto next person who wants to RP as antag, and the cycle likely repeats. Even if there's nobody too validhunty on, an antag might gun down everyone, and someone might start being validhunty. It's a problem on both sides.
Hell, a good lot of sec players have urges to validhunt, As seen as my time pretending to be a biesel government inspector. Most of them, in LOOC, At least if I remember correctly, said something along the lines of "I'ts so fucking hard to not shoot you right here, right now", along other things. Additionally, I've had an experience when, After trying to RP as vampire, and succing once and fucking up, The rest of the officers arrested me, of course. I was brought to medical eventually, for some reason, to examine my eyes and see why they were flashing. Meanwhile, the fucking psychiatrist was trying to straightjacket and muzzle me and haul me off to his office for being insane, while he clearly saw the flashy bs and saw the scans were clean. I had to flash him again and again to keep him off of me. He eventually shot me with a syringe dart and got arrested, but at that point, security decided to hand me over to medical, where I got my eyes cut out. FYI, the person I succed? not dead, perfectly fine. Assault at most. They decided, instead of blindfolding me, or just cuffing me normally, to have medical cut out my fucking eyes. Yep. They cut out my eyes. And I spent a chunk of the round near dead, eyeless, and in cuffs. At round end, I think I was still arrested, dead, or left out of stress. All "Valid'. Frustrating as hell.