Because 2/3 of the time it's a -good- bonus
With a +1, you have an even chance of getting any number in the 2-7 range - this is a 1/3 chance of overshooting, with a 1/2 chance of that being a critical overshoot. Chance of minor fail (2 or 3) is 1/3. Chance of non-overshoot success (4 or 5) is 1/3.
With a +2, you have an even chance of getting any number in the 3-8 range - this is a 1/2 chance of overshooting, with a 2/3 chance of that being a critical overshoot. Chance of minor fail (2 or 3) is 1/6. Chance of non-overshoot success (4 or 5) is 1/3.
With a +1 1/3, you have an uneven chance of getting any number in the 2-8 range. (2: 1/9, 3: 1/6, 4: 1/6, 5: 1/6, 6: 1/6, 7: 1/6, 8: 1/18) That's a 7/18 chance of overshooting with a 4/7 chance of that being a critical overshoot, 5/18 chance of minor fail, 1/3 chance of non-overshoot success.
So your chance of a non-overshoot success remains constant, but going with a +1 1/3 over a straight +1 increases the chance of overshooting, and increases the chance of it being a critical overshoot when you do. Raising your bonus beyond +1 implies that you prefer critical overshooting over a minor fail.
And that mentality can and probably will lead to an eventual +1 2/3 bonus, since 3 skill points are easier to get than 20 tokens, assuming you don't end up dead in the meantime; that changes the theoretical outcome chances to 2/9 chance of a minor fail, 1/3 chance of a non-overshoot success, and a 4/9 chance of overshooting (and 5/8 chance of critically overshooting when you do).
Do you see why I said "+1 1/3 Exotic bonuses strike again", yet?
Bleh, 12 posts in the meantime. Let's see if there's anything I disagree with/a ninja in there before I post this.
Okay, so, people seem to be having trouble remembering just where everyone is: I've been tracking this through the turn posts with a spreadsheet since this event started, so I'll just copy that in here, so people know who's standing next to the overload and who isn't.
Xantalos, Wolfkit, Pufferfish, Tavik Toth, solarlight, Execute/dumbo, Pancaek: Hallway (rec room). That is, they're in the hallway outside the rec room. Pancaek hasn't moved for a few turns, since he's been tripping on Xenospit, but he collapsed after leaving the rec room, so I assumed that's where he was. kj1225 may or may not also be here, since his action was to go look for "spookiness", and piecewise responded with "does the sheep count?". If piecewise is in a generous mood, he's still at the infirmary doors, instead.
Persus13 is outside R&D, and as far away from the overload as is currently possible.
Unholy, Spinal_Taper, Dorsidwarf,
Omeganaut: Barracks. Bolded Omeganaut because piecewise has him placed in the hallway outside the rec room.
And Hasala isn't on the sheet because I figured it would be redundant to track my own character's whereabouts, but yeah, he's in the briefing room.
EDIT: Omeganaut's last two actions, for reference:
Omega hails the humanoid. "Are you a member of this crew? If so, I recommend searching the other direction, as the other geniuses are repeatedly searching a wall, even if there used to be a door there. Obviously things aren't the same." Omega searches the corridors back towards the science lab and pod room, if those still exist.
The pod room is the barracks and it's still there. Though there are no pods, just a blank wall. You do, however, find some naked guy laying on the ground in the middle of the room.
Omeganaut sighs. "Alright, this has to be hallucinogenic gas. So, since I can't seem to open the maintenance doors, I'm just gonna sleep. G'night." Lays down and attempts to sleep.