It’s an issue when some (in this case) the Dad does not know good from bad, apples from oranges and so on.
They can’t see long term results when they walk into a facility (though the dad should be able to see that through his son’s results with you) they only see cones, gadgets, toys and so on that we know don’t mean much in developing an athlete but they don’t. They see what’s on the surface and not much else-it’s very superficial.
Because they don’t know enough about the subject matter they believe that simplicity and low to moderate volumes can’t be enough to be an effective program-wrong again.
They also reason that if a coach is employed by team x and they are in some top league then he must be the best. Wrong-not only is he possibly not the best but he might not even be all that competent but then the guy who hired him likely knows little of the subject of s & c either.