My ceremony site is on a lawn with a lovely view behind me. It doesn't look lovely inthe foggy picture, but the site overlooks the Monterey Bay, I swear

My Mom, MOH, and BM's all think I need to have something around or over us for the ceremony. Like an arch, or flowers or pedastals, or something...
I'm on a budget, so this seems like a waste, and, at least to me, the ceremony is all about me and FI and our exchange of vows. We are having a very short ceremony so the area will only really be used for a short amount of time.
We're having the ceremony and reception at my bosses house, so there really isn't anything available from the venue. If i were to use anything it would have to be bought or rented.
What do you guys think, are they really necessary?