That's a common misconception, that you can only control your own actions and are powerless to control everyone else. In fact it's false and is one of the first things you learn as an advanced driver/rider. None of us exist in a vacuum and our actions influence other road users, whether we want them to or not.
In the case of the filtering motorcyclist you can choose to do nothing, help or hinder. Unless you drive to work in a Hummer there is easily enough room in your lane for your car with space left over for a filtering bike. You can increase the 'filter space' by positioning your vehicle further to the left or right of your lane as appropriate, regardless of whether or not the lane alongside you is already occupied.
Please remember that all the motorcyclist wants to do is get safely to the front of the queue. They don't want to annoy you, scare you or hold you up. In fact, if they see you deliberately make space the chance is good that you'll get a friendly wave, nod or even leg-wave.
(sometimes you can't take your hands off the bars to say thanks)
You should also bear in mind that the space the bike is filtering through is probably significantly wider than you perceive it to be. The width of your car is extended significantly by your wing mirrors. The thing that most often stops me in a queue is where 2 cars are exactly side by side with wing mirrors level. There'd be plenty of room to get by if either vehicle would move forward by a foot or so, but all too often they just sit there, staring straight ahead while blocking my progress. Do I use that example to say that car drivers are idiots? Of course not. As a road user it's my job to deal with the situation and move on.
As a matter of interest, how do you know that the gap the bike is squeezing into is 'too tight'?