You are probably right in that I most likely lost a big part of my soul while adopting this philosophy. But every since I've started treating non-personal interactions in the same way I would treat compiler errors, I've stopped having a strong urge to drink after work, and overall can focus on what is important to me outside of the 9-5.

The only thing that really can get under my skin at work anymore is if a situation starts to threaten my job (i.e., backstabbing, gaslighting, setting up for failure, etc). But with this newer approach, I'm able to recognize this a lot sooner and do something about it.

Another way to approach this if you don't like the cold impersonal "API" approach, is to convince yourself that you are playing the part of a character in an improv style play. That the people being "mean" to you aren't really mean, they are just acting. Of course the danger with this mindset is that you could end up inflicting emotional harm on someone else without intending or realizing it.