There's a guy in my neighborhood who has stubs for arms. Maybe he was one of those thalidomide babies. I don't know; I haven't asked. This guy has a wife, a career, grown kids, etc. He is completely normal. The only times he asks for help is when he's going on vacation and wants to know if our kids will watch after his dog. I remember when I first met him, and I was like, woah. This guy has no arms. I kept an eye out when he was out, ready to jump in and help him out if he ever looked like he needed it, but frankly, the guy seems happy enough, capable enough, and independent enough that I sure as hell am not going to stick my nose into his life and tell him that I'm there to help. That would be tremendously rude, in my view. He's a grown man. I respect him. We're friendly. If he needs anything, I'm sure he'll ask. I may be pretty clueless about human relationships a lot of the time, but at least with my neighbor I'm not going to make disrespectful assumptions and talk down to him. Now if he was keeled over in the middle of his yard, clearly in distress, that's different. I certainly hope I'd lend whatever aid I could, but that's true whether or not someone has arms.
Sure, there's a lot of nuance, a lot of ambiguous situations where you might think you see a need and try to address it, only to make things worse as kstenerud pointed out, or you could mis-perceive a situation and not address someone's need, only to perpetuate someone's suffering like in abusive situations or something. I don't know. It's a tough call. Still, better to try to make those calls while at the same time acknowledging that you might be doing something (or not doing something) not (just) to make someone else feel better, but to make yourself feel better about yourself. Self-deception's an easy trap to fall into. When it doubt, not only do you have to do the Right Thing, but you have to do it for the Right Reasons.
Oh! I thought of another example. The other day when I got off work, I saw some other neighbors raking the leaves in my yard. Now, I know they were doing it to be nice and that they don't have a mean bone in their body, but let me tell you, I felt totally embarrassed, like here were these two completely nice people, raking the leaves in my yard because I clearly can't take care of it myself. I mean, I'm a grown assed man. I'm completely capable. And I felt totally emasculated.
And here's another example. I try to help my wife with computer stuff whenever she runs into problems. She's a former software engineer, and it totally pisses her off. She feels like I'm being condescending to her. But I'm not! I'm just trying to help! But I think I end up making her feel less for not being able to do something, and that's not right. If I do something in her life, it should be empowering, in dis-empowering.
I guess my point (and perhaps kstenerud's) is that you can "other" someone - alienate, disrespect, and disenfranchise them - in the guise of being helpful. Without really knowing someone or their situation, without having that relationship or trust or whatever, making the right call is super difficult.
(I know it's eroge, but you should check out Katawa Shoujo some time. Play it on PG mode if that's what it takes. You might find the game's different story lines insightful in the context of this discussion.)