This is interesting. I think you have a good point there: it's actually a psychological disorder ... At the mild end they are people pleasers. More extreme and they are codependents.
But I'm disagreeing with all the stuff about absorbing others' feelings. Autistic people often say this too: that they feel other people's emotions and get distressed by them. This would be a supernatural ability. It doesn't exist.
My view is that it's down to inadequate sensory filtering. Autism causes distressing hyper-sensitivity to all sort of things like sounds, smells and textures. It's normal to feel irritated by a rough seam; only someone with a neurological impairment finds it unbearable. They might feel like the seam's attacking them, but they learn soon enough that clothing has no mind of its own so their own sensitivity is the problem.
That logic's harder to access when the irritant is another human! They might find it easier to believe they're feeling Sally's sadness, but they're not. They're feeling overloaded by it. It distresses them because of their social processing disorder, and they choose to interpret their distress as Sally's. This can be singularly unhelpful.
I've known a few people who, having come to terms with this in themselves, will say they're not suited to give the right kind of support but will make some tea or bring a blanket, whatever. One of my best friends refused to help me when I was miscarrying - I wasn't too thrilled, but had to respect that it was better she said so than tried, only to then need my help!
It might be interesting to know whether 'empaths' and 'highly sensitive people' have abnormal physical sensitivities as well. Others, I think, are emotionally maladjusted as you said, needing to be needed.