Object move 2 clicks with lmb select where rmb select only needs one click

When using rmb select blender can move objects while holding rmb pressed (one click). But with lmb selection the user has to select the object first and then click again (two clicks) to move an object.|
Is there a specific reason for that? Or can this behavior be changed?

We would like to have the same behavior with lmb selection.
We are working on an addon to improve rigify and this is an issue that needs to be resolved.