There is no statistical evidence to suggest that burka's hamper efforts to identify citizens any more than wearing a large hoodie, hat or scarf might, but nobody is discussing outlawing those items.
Regarding the claim that anyone could wear a burka to carry out terrorist acts, there have been no cases in the UK of anyone wearing a burka purely to carry out a terror attack undetected. In fact, globally there has only been one anecdotal case of a male wearing a burka to commit a terror attack. That was in Yemen. 
Cases where criminals use burkas to hide their faces are also rare. There is also no reason why the criminals couldn't use another disguise instead. A former Anti Terrorist officer for Scotland Yard went on record and stated that he didn't believe a burka was a security threat.
The argument for banning the burka on security grounds also falls apart when it is not extended to include other face coverings and hoods. It reveals the anti-Islamic agenda held by many proponents of the burka ban.