I don’t know how long ago this was, but regardless, I get the impression that a lot of the anecdotes related in this thread cover a wide span of time, from decades ago to more recent. In any event, many of the rules and guidance that are now in place for Eagle Scout service projects are to make the process more uniform and consistent between troops, districts, and councils.
As I
[quoted]
(https://boards.straightdope.com/sdmb/showpost.php?p=21567356&postcount=7) earlier in the thread, a blood drive with canned instructions is specifically mentioned as an example of a project that would not satisfy the current requirements for an Eagle project.
Conversely, the guidance about there being no minimum number of hours required is because some troops, districts, and councils were requiring projects that were ridiculous in scope, sometimes in an effort to one-up the others or to make themselves look better.
I reiterate what I said earlier about the outsized importance of the project as perceived by the public. While the Eagle service project is important, it’s by no means the only requirement. See here.
To take one example, to earn Eagle Scout, Scouts must earn at least 21 merit badges in different subjects, of which 13 are required (e.g. Citizenship in the Community) and 7 are electives. (Most Scouts end up earning far more elective merit badges than they actually need.) One of the required merit badges is an option between Swimming, Hiking, or Cycling. Nobody completes the Swimming merit badge without learning how to swim, and merit badge counselors (usually at summer camp) take this seriously – you are otherwise putting the Scout’s life at risk. However, some Scouts (for whatever reason) simply never learn to swim well enough to complete this merit badge, so they can also do one of the two alternates. The Hiking merit badge requires a total of six hikes (plus other requirements), including one 5-mile hike, three 10-mile hikes, one 15-mile hike, and one 20-mile continuous hike which must be completed in one day. The Cycling merit badge requires two rides of 10 miles each, two rides of 15 miles each, two rides of 25 miles each, and a 50 mile ride which must be completed within 8 hours, as well as several other requirements. All of this concerns just one Eagle required merit badge. There are 20 other merit badges which must also be completed.