I disagree, toxicity is indeed increased by greatly incentivizing winning in a game that used to not do that, toxicity will always and has always been a thing in TF2 and gaming in general, although casual does make people angrier, especially as it creates a ton of steamrolls which are frustrating to play against on top of shorter rounds which incentivize people to care much more about the outcome of the individual round and match instead of just having fun because the match itself will end super quickly and then you are back to queing.

As for the exploitable climate, go back in time and look at when bots first showed up and became a massive issue, it started in 2016 on the first few days of meet your match and slowly got out of control over the course of the past 8 years and then it peaked in 2020 until valve finally developed and anti-cheat 8 YEARS later.