When using tools like Explode, I see this notice:

Other tools are like this as well. When the tool is specific to certain kinds of features, it makes sense that they should be filtered out.
I'd like to see Merge Parcel Points behave this way. I use the tool on a daily basis, and if I'm not using the "Select Fully Within" mode, I get all my polygons and lines selected as well, which can make it difficult to see what I'm doing.
I could turn the layers off, but I like to see them to help determine which point is supposed to be preserved when merging. I could make the layers not selectable, but that's a time-consuming process. I could create a separate map even use Tasks to make the other layers unselectable specifically for using this tool.
These workarounds seem hacky and time-consuming. If the tool simply filtered my selection to point features only, it would be a definite improvement.