It's the only way we can see. We can safely assume there are personal, political, institutional contacts that we can't see, more informal than formal. Formally, the mmeber states get involved in "codecision" with the EP after the Commission is done with it. But there's more than what's formally codified. We might even be able to get somewhere as citizens by writing directly to the commissioners, we just don't know that. If a commissioner were or had been your elected representative back at home at some point you might have a better shot than others.

Nothing is 'mere'. — Richard P. Feynman