My INTPness is in question, but I'll answer assuming I am. I work in behavioral health. I've been a direct service provider and a program administrator (and frequently both at once). I've also been a teacher, and I've done ABA work.
Ermagerd.
It's stressful because a lot of the duties are in direct conflict with your preferred at-rest state.
1. Responsible for the actions of others
If someone does a thing, you have to do a thing in response to the thing, even if you don't want to do the thing. Sometimes you're really unlucky, and get in direct trouble if the person does the thing.
2. Responsible for timely and thorough documentation
Any time you are working with vulnerable populations, you have to not only use documentation to keep yourself safe, but to also justify your continued employment. If that wasn't stressful enough, the paperwork is hefty, and the time constraints are pretty unreasonable.
3. It's draining
Just the sheer amount of talking involved is daunting. Sometimes I'm too drained to even listen to music. I just need silence. But it's not just the socialization. You have to be at your best at all times. Bad days are not acceptable because even minor displays of irritation, impatience, or pure exhaustion will have a disproportionately negative impact on the person(s) served. Of course, here, we have an advantage over our more passionate counterparts, but it still takes a lot out of you over time.
4. You will be less effective with most people
It's true that we have a lot of potential when it comes to helping someone understand and change themselves. We're naturally nonjudgmental, perceptive, and respectful of others' autonomy. But we do all these things at a distance. We'll never bond the way other providers can bond. We can be role models, we can be supports, but some people need to feel a kind of emotional connection that we can never provide. To feel truly understood and accepted. The best we can do, is give them a knowledgeable and caring robot.
Argument in favor: this field needs us.
Most people in "helping" professions are doing it for emotionally selfish reasons. Maybe it makes them feel good to help others. Maybe they want to be a hero. Maybe they want to boos people around. No matter how altruistic it may sound, they're doing it for personal satisfaction.
So if they are working with someone "difficult", or "ungrateful", it can become pretty toxic pretty fast. They most often find an excuse to avoid/neglect the person, but some will become vindictive, passive-aggressive, or downright mean. Not all workers, maybe not even most, but enough that "the system" is a categorical source of trauma.
We are better than most at sitting in the fire without getting burned. Our extended capacity for detached involvement allows us to truly extend unconditional positive regard to people who need it most. It also gives us a fresh perspective in a field dominated by SFs.
