Are you sure you got 2 quarts out?  The drain is where it is because its just about the lowest point so it all gets out.  This seems to be up a bit unless you jacked up the rear tire but theres no way thats easier than freeing that plug.  Another thing to consider is the reason the magnet is on the drain plug is to collect metal debris.  Mostly clutch if Im not mistaken.  If you dont get that out youre not removing what the magnet is collecting.  Just food for thought.  

Edit: as for the extra oil sitting, Harley sportster never get all the oil out.  They tend to hold about .5 quart.  So my issue wouldnt be the spare oil you arent removing its more cleaning that magnet on the plug.

That is not a drain plug - it is a threaded plug over the hole that was used to drill the passages in the engine for the oil to flow to/from the filter.

You may have gotten 2 quarts out - but there is a lot of oil in the sump that you didn't get out.  Look how that plug you removed is almost at the same level as the oil window.....there is a lot of oil you didn't get out of the engine.

You should be using the drain plug that is on the bottom of the engine to change oil......as it is low enough to get nearly "all" the oil out of the engine sump.

And....it is unfortunate that so many people over tighten the drain plug on engines.  The bolt should only be made firmly snug - not tight.  The bolt only needs to seal - the bolt does not hold the engine into the frame!

I have all my drain plugs drilled for safety wire now.
I use to ham fist drain plugs, ( I was scared they would fall out at some point).
But now it is torque wrench and safety wire.

I was more worried about front brake bleed screws.

True,
If your oil drain plug falls out, your motor dies.
If your front brake bleed screw falls out, you could die!  :'(