This is insane in 2015. I understand the difficulties of porting, but at the same time, I've had a 64-bit CPU since 2009 and I was late to the party :)
I really, really, REALLY hope that Unity fixes their editor UI in version 5 (I haven't tried the beta yet, so maybe it's the case already), but as it stands right now I can't use Unity for long stretches (visual impairment). The font rendering in the editor is terrible, even at 1920x1200 the text is too small (froget about Retina even). This has been a problem with Unity for YEARS, which is a shame because it's a great tool otherwise.
I'm still torn between the two tools, they're both fantastic for different reasons, but if Unity 5 can't fix their editor then I think I'll have to jump ship just out of necessity.