You make some really valid points, on both the pros and cons from both camps. As full time video operators, we are always aware of the pro togs needs and allow them room to work. Sometimes we both cross in front of each other, but normally accidently.
Most current problems stem from the rank amateurs (I've got a 5D and and I'm a wedding photographer) who are more of a serious nuiscance in Church. A definite lack of respect there and the scene is set for the rest of the day.
Consideration for others is well down on their agenda and the newbies, like their video counterparts, create future problems for every pro, who, as a team player on the day is working for the Bride and Groom. But not at the expence of other service providers.