That's not true - his arguably best position was CB, CDM and LB in that order. Him at United was used differently than a position that enabled him to play in his best position consistently.
If he was allowed to fight for a CB spot under Jose - hell in a back 3; Blind would be fought for by clubs who play that formation. He didn't try & fail at playing at CB - he was not given the opportunity by Jose just because Jose has the inability to use a player like Blind.
We saw how he bought the best out of Smalling & every other defender we have in our squad apart from Lindelpf has the same strengths & weaknesses as each other. Pacey, strong, heading yet inability to remain calm under pressure, right positioning & passing. Put 2 of them inbetween a player like Blind - we would have a better defence than a lot of the teams with an ability to initiate attacks from the back.
The fact is that Jose has an inability to change his methods to inccpperate a player like Blind within a team - defensively he needs a player like Terry - not his legendary footballing status but more of a last line of defence type defender when the rest of the 10 players have failed to defend as well.
Blind's inability to move to a big club is because he only got to play CB for 6 months - a position he was deeper & more astute at than when he played CDM for us.