I still don't get it. Why would anyone waste any time calculating "median"? It's completely worthless.
Median exists for a reason.
Re read to understand my points, now you see it is logical. But with no activation there is no adoption.Is that correct?
Well, obviously. If the Segwit soft fork does not get activated then there can be no adoption. However, I don't see a reason for which it should not get activated.
(bitcoinfees.21.co also quote this 226 "median" number?)
Yes, that is the median TX size.