oh man, gonna respectfully disagree. a million little things that cause slow play, knocking in a "gimme" and bending over to pick it out of cup is the least of those things IMO.
honestly, if your round is taking for ever then you ask to play in front of the group in front of you. most likely, there will be a group in front of them so someone, some group, FAR up ahead, is causing the issues.
i truly think its for the most part, courses just sending too many people out there with not enough time between groups. this happens in all walks of life, not just golf. put 100 cars on a road, everything is smooth, no traffic, everyone going where they want. put 400 cars on same road, there is traffic and cars are inching along.