Thank you, @eloquent, for putting that far more eloquently than I ever could have.
I wanted to add that in terms of discrimination, just look at the social institutions around you. Look at some of the examples I listed. Wheelchair bound folks forced to go around/take the long way at so many places where accessibility wasn't built in as a top priority. There are many places where there is NO accessibility at all, and thus they can't access it, period. It's definitely not equal.
And back to empathy - I'm not arguing that you shouldn't show a disabled person empathy. In fact, I think it's a good thing in general to show most people empathy. I'm not going to comment on the myriad of assumptions you made about my father and his life, but I just want to say that you haven't been particularly clear on how you plan on giving people hope. And that no matter how positive the interaction, if you attempt to give people "hope" while maintaining very clearly that they are the "other," that they are "different," (which you seem to indicate by how TRAGIC their life is), such an attitude may not give hope at all but instead make folks feel worse by singling out their differences. Maybe it'll help some, but not others, but in your post you have generalized and objectified them all to "those people" and are giving this advice applied to this entire group, so that's the issue here.
tl;dr there's nothing wrong with being empathetic. The issue is that you've lumped all disabled people into one group, assumed they all have the same experiences, and then forced a TRAGEDY label onto this group... this is by nature not very empathetic