In all my flying, I have never done that. I feel that the space in front of a row is for people seated in that row and should not be used by people as thorough fare to go from one aisle to another. I rarely sit in the middle section of bulkhead seats, but even when I am not seated in the said bulkhead section, it irks me when I see passengers using that as if no one was seated there.
What do you think?
Sometimes they trip over some one's leg, shoes or some other item. Once a passenger tripped over my CPAP hose.

On another occasion, we were seated in business class, my wife and I in window and aisle and my kids in two bulkhead aisle seats in the middle section. The FA parked the newspaper trolley in front of their seats, making it difficult for my son to get up to go to the restroom when he needed to go. A few seconds would be OK, but I really don't think people should intrude into space being used by others. I never expected it from an FA.