So while it makes a lot of sense to grab inside the object to move it, IMO it actually makes less sense to grab _inside_ the object to resize it. (Imagine the reverse argument -- IRL you can actually grab the middle of the plate to move it, but if grabbing the middle of the window resized it, that would also be very bad.)
I've been trained to grab the edge to resize windows. So I wouldn't try to reach so far inside the rounded rectangle as OP, although it doesn't invalidate their entire argument.