You would also have access to their development branches which would give insight into future product features and bug fixes that have not yet been released. The former would be useful information to give to competitors and really put the company into a tough position to compete down the line while the latter could be used to find possible critical holes to exploit.
Who says a competitor has to be the one to exploit security holes? It is much more likely that the source code would be sold on the black market to those who have no qualms about doing this for gain.
