Well, in SW they
were knowingly firing upon a ship with a Senator on board. Now we know why they were so pissed.
And it's not like the gambit was completely without merit:
"If word of this gets out, it could generate sympathy for the Rebellion in the Senate"
Just
mostly without merit.
But desperate folks in desperate situations and all that.
----
As I understand it one of the plans*, such as it was a plan, was to expose the Death Star to the Senate and the galaxy at large before the Empire was ready to openly use it. Trying to use Leia as cover was a "It probably won't work, but if it does..." type deal.
Otherwise known as: When all you have is crappy options, you pretty much have crappy plans.
It was only when the Senate was dissolved did the Empire think it could get away with the open existence of the Death Star.
So, like I said, works well enough for me.
* Along with the "Search the Files for a Weakness" plan and "Open Full War is a Comin', Get All Our Allies Out of Cold Storage" plan.