I am appalled that yet again one of my colleagues has proved to be so lacking in sensitivity. All Church of England priests are not like the rector you describe, thank God. Of course there are rules, but there is also common sense, and common decency and there should be a bit of care, even love, shown to people who come asking for what to most of us sounds perfectly reasonable.
I have had charge of four churchyards over the years, and in all of them there are gravestones that are not allowed - heart-shaped, book-shaped, shiny black, and other banned designs or materials. Many of them were installed before I was the parish priest, and several certainly during my time there. I am not a plastic flowers fan, but I would never remove them from a grave. I assume that the folks who place them on graves do so because they help them in some way.
I don't think we have the right to be the taste police.
The Rev BRIAN SAGAR