Yes it's a horrible thing, yes it's horrible to tweet about... but you know what, it's also horrible to try to act like it's just not a hinderance and this kind of thing needs to be called out. It's great, in fact it's easier! No, it's not. It's significantly harder life. Nobody thinks "man, if I just woke up tomorrow without the use of the lower half of my body my dating life would be so much easier" because it wouldn't be easier, it'd be a great hurdle. In fact nearly everything would be harder. Again this doesn't mean you can't find happiness or that nobody will ever like you for you, I think that's literally impossible in this world, but this is unfortunately sure as hell not an easy path to either of those things. <- this also means you don't have to be in the same situation to not be "ashamed" of your partner, though some may certainly be it's not a requirement of how society operates.
I'm not sure you can make the jump "you could say the same thing about trans people" (more power to you) as the alternative to being or liking trans people is lying to yourself about who you like while the alternative to being disabled is being abled. One is all about who you are attracted to and who's attracted to you, the other is about being able or unable to use part of your body. Of course being true about the former leads to greater success in dating, the latter seems a bit of a stretch.
I've had partners who were ashamed of me before. My current partner isn't but still gets grossed out when my joints dislocate, though they know it's bad and try to help me when that happens. It varies.
Also, disabled people often date each other, which comes with some downsides (like not having an able-bodied partner to be a caretaker), but means you're shielded from that icky stigma and you don't have a partner who's ashamed of you.