I can't see the point of having one only for a home table.
But yes, when you are travelling, I think they are a good idea.
If you travel around and play in snooker comps, all the bridges supplied are basically the same and so as a player you are familiar with them.
Travelling around to play in 9ball / 10ball comps, there are so many different bridge heads it's unreal.
So carrying your own means you can use something you are familiar with.
The one I have, and my favourite, is the one alot of wheelchair players use that was derived from a golf ball retriever.