You've made a bunch of Markers along a long clip and now want to Batch Export them and find that you can't because Batch Export in the Menubar is grayed out and right-clicking on them in your Bin doesn't show Batch Export either.
No problem; you have two simple solutions:
Highlight all the Markers you want to Batch Export and hit Command + U which will turn them all, instantly, into Subclips. They'll be loose in your Bin so prepare for the mess early by naming the Markers something helpful before you do this.
Then Batch Export away.
Create a new Bin (Command + B) in FCP's Browser and then drag your Markers (helpfully named) into your new Bin and they'll automagically turn into Subclips.
I like this method because it helps a project stay organized in the Browser window.