Problem is that only few people can starve base to death with blocking docking during shield on. Now, when you siege a base, you need people in a perimeter around and blowing up ships when they appear. But they have a chance to run through blockade and supply.
After change, there can be only one fighter pew pewing base which prevent anybody from docking. Funny fact - if there will be much fuel and less repair material (ship hull panels etc), the base will die due to automatic damage despite the shield has enough fuel to be on. So if some people are willing to spend a weekend to siege your base, you can do nothing if you don´t have a lot of friends with fighters who kill them.
Really, this is a punishment to non-hidden bases which are trying to make sense for player bases (trading purpose etc). What will be a result? All bases will be hidden somewhere in remote systems. And people will be more suspicious, distrustful and paranoid than they are now.