I'm afraid the statement that "every programmer tests code" is not a fact. Not by a long shot.
In fact the vast majority of bugs are the result of not testing changes at all, in any way shape or form. Committing code changes without even running it (or only running it to the most simple and predictable of scenarios) is not an exception.
Many programmers, especially those that don't like writing test, simply assume it works "because it was simple". It's this utterly unrealistic and unprofessional hubris that gets condescending reactions.
Given the damage it does to both the product at hand and our profession in general, I would say condescension is a rather mild response to this behaviour.
> In fact the vast majority of bugs are the result of not testing changes at all
I never said every programmer tests 100% of their code all of the time. Even when you're just checking the output of a "hello world", you're effectively testing your code. It might be the only test ever made, but it is a test.
> In fact the vast majority of bugs are the result of not testing changes at all
Now you're making a bold claim that, AFAIK, isn't backed up by research.
Just to be clear, I like tests, and I like automated tests even more. I just don't think they necessarily merit 50% of my own time because they're not some panacea that will magically auto correct badly designed software. Test are written to find bugs, not to eliminate them altogether; you can't guarantee your code is bug free because of tests.
At one of my past jobs, the threshold for "should I commit this?" was "does it compile?". The rationale was that if there were problems with it, they'd be caught during "acceptance testing" (which was probably 6 months down the road). I didn't stick around for very long...
I've seen PHP committed and deployed to production with syntax errors, which means nobody ever tried the offending pages even once. I also left that shop pretty quickly, because I don't think options keep vesting if I garrote somebody with a network cable.
In fact the vast majority of bugs are the result of not testing changes at all, in any way shape or form. Committing code changes without even running it (or only running it to the most simple and predictable of scenarios) is not an exception.
Many programmers, especially those that don't like writing test, simply assume it works "because it was simple". It's this utterly unrealistic and unprofessional hubris that gets condescending reactions.
Given the damage it does to both the product at hand and our profession in general, I would say condescension is a rather mild response to this behaviour.