When hotspots were rendered not via webGL, I was under the impression that, on iPads for instance, the more hotspots that were loaded, the more layer lag there was. Removing a hotspot instead of disabling it would have made more sense perhaps.
Now I'm generating hundreds of hotspots within 1 pano, all alpha PNG's and distortion and even old iPads don't break a sweat. So I don't think that under normal circumstances it actually really makes a great difference.
From a coding perspective, I like to actually remove elements instead of hiding them. It seems more elegant.