because the NBA discriminates based on height, that their pool of good athletes is much smaller than soccer's pool of good athletes. I wouldn't dream of disagreeing with that.

What I'M saying is that the OVERALL skillset required to be elite in basketball contains facets of athleticism that the sport of soccer simply does not, regardless the height of the individual or likelihood of him swimming in the talent pool. If in some (sick, frightening and twisted) world where handball was as popular and drew as much athletic talent as basketball did (thus neutralizing your height argument), even if that talent pool was still dwarfed by that of soccer, I'd still submit that the basketball-on-the-ground sport produces better overall athletes, because they are the most athletic in the world at a sport that required them to do more with their upper-bodies than simply provide the counter-balancing ballast required to run quickly. If, on the other hand, in this strange world where a non-height-requirement-basketball-type game attracted equal athleticism pools, I can't begin to think how ANYONE would assume that the sport that uses no hands produces better athletes, if they consider upper-body strength, agility, and coordination any part of athleticism at all.
(Note here, just so nobody misunderstands, I do NOT think that current elite Handball players are anywhere close to the athletes that NBA or EPL players are. I was merely using a sport similar to basketball that did not discriminate on height to illustrate the advantages having and using the space between ones hips and brain has in making one more athletic overall).

As it is now, with the requirements of the two sports, basketball and soccer, the skillsets that make a player elite (no matter how many more or fewer other guys he had to beat out to get that title) are varied enough that in my opinion, the upper body strength and precision that a basketball player develops to an elite level, regardless his size, more than makes up athletically for what he concedes simply in raw speed. The fact that there IS a height and size discrimination in basketball makes the comparison more stark. An Allen Iverson, for example, is probably approximately the size of your average EPL soccer player. IMO, an Iverson would beat a soccer player of the same size at the upper-body strength and skill events handily. Put 6 inches and 30 pounds on top of THAT, and LeBron destroys Iverson in those events, leaving the average soccer player in the dust, but is still run-fast-athletic enough not to be left near as covered in dust at the 100, 400 or 1500.

As you say, we agree to disagree, but the above seems much more compelling to me than "I'm sure they'd be good at something that their sport has never required them to do because they look buff with their shirt off."

If athleticism is running in a straight line, soccer wins. If it's anything else, basketball beats soccer.