TLDR; 2 issues: 1, sports have other limiting factors, league has fewer so it's probably knowledge limiting someone on some level; 2, if we are talking coaches who are great strategists, but not players, they played high school varsity probably which is at a minimum probably top 25% of the population of people who play that sport, so they would be low gold on the ladder in league.
I think it's definitely a good argument and a lot of people disregard information they shouldn't just because it comes from someone low elo. However, let me play devil's advocate for a moment.
I think the analogy of coaches in sports is a great example of the concept that sometimes it isn't the best players that create the best strategy or macro level game play. However, in the interest of providing a legitimate counter point to be refuted if the original argument is indeed the best, let me argue two issues that were overlooked here.
The first argument I would counter with is that there are different limiting factors between progression in sports and progression in league ranks. If you're short you will not play high school, let a lone college basketball most likely. However, the only real limiting factor in league is reaction time. There are a host of physical attributes a good player may lack (in addition to reaction time), which keep them from progressing beyond high school sports, but there are minimal limiting factors which can keep a player from being able to progress in league if they are able to understand the game intricately. Yes there are some players who will have slow reaction times, or cannot focus for the length of a league game, and are great at theory crafting, but they are a smaller proportion of the community. Therefore it is highly likely that a low elo player picked at random will have significant deficiencies in game knowledge and strategy concepts compared to the skills of a high elo player. This creates a lot of bias that has to be intentionally refuted by players who intend to seriously consider the advice of bronze players.
The second, and more interesting argument is to look at what high school ball would be considered in terms of elo when we are discussing coaching and game theory. The vast majority of sports coaches played at a minimum of high school level if not college ball, and then generally build their coaching experience over years of being a position coach or assistant coach before becoming head coach. So pro ball is the challenger level (maybe the bench or developmental leagues are masters?), but what level is high school ball? You're stating that bronze players may be similar to esteemed coaches because like coaches, they can't play past a lower level, but may have good strategy or theory. However, there is the consideration of things like rec sports, and middle school sports, and how many people get cut when we move from that consideration to high school. If we assume that almost all coaches played their sport at at least varsity high school level skill, then we have a comparison point. We have already dropped everyone who only plays rec, and anyone who didn't practice enough as a kid to continue on in high school, then we drop everyone who doesn't make it off the freshman team, and everyone who never makes it past JV. We have maybe 25% of the population of people who "play the sport" left by varsity high school (probably less)? Coaches understand the game enough that even if they aren't good they make the bench on varsity because they can be position players, or because they help the team understand plays and are useful in practice to get the team better and more coordinated. So if this is the minimum level most successful coaches play to in sports, what does that translate to in league? Well where is the top 20-25% of the ladder? The cut off is low gold (and I mean gold mmr, not gold ranked, but plays against all silver teams). If we assume that varsity high school is a smaller % of the players for that sport, then suddenly we may be talking plat or low diamond for the level that successful, high quality coaches come from. In this model, low elo players may have a good idea, but it is likely to be akin to a trick play that is interesting, but doesn't match up to knowing the whole game well enough to coach.
I'd love to hear counter points, because I think there are some good ones, but I like to only take one side of the argument in socratic discussion (pretty sure that's the model, but then I didn't pay attention in philosophy as an undergrad because seriously who uses philosophy class ever?).
for the mana regen, you feel me?
or 
is sooooooo much better than those 2. Even if you fuck up cs, you still get gold! Worth.
