Everyone has different needs and goals; they don't have to make sense to you.
I know, but comparing 2 lenses, what is the purpose? I have 70-200 mkII and i have 135L and 100mm Macro, i can compare thme 3 but then what, just to conclude that one lens can make other lenses redundant or just to have a reason/excuse to get rid of other lenses?
Well, even if i get that FE 70-200 for Sony, then what i can do with Canon 70-200? and if Canon brought a camera that is almost same IQ as Sony A7/A7R [24/36mp] then i may think to have Canon 70-200 mkII again and get rid of Sony FE 70-200 because i am back to Canon.
Also, what is good about FE 70-200? I mean, is it fast AF so it beats Canon 70-200 f2.8II? or it is barely not that much fast AF then Canon 70-200 with Metabones adapter is not that bad then, i can understand only if you have Canon and Sony without many lenses around then sure i may think about Sony versions, but if Canon shooters with lots of Canon lenses trying to move most of their glasses to Sony FE too, what gain if they lose their Canon then one day Canon make them back with new camera say that is 30-40mp? I will always go with Canon if they can bring that camera with 36mp or higher as with Sony A7R and Nikon D8xx series, just because Canon didn't have one yet so i try to make Sony as my main body then it control my lenses plans too.