This subject will be debated for years and years to come. I coach in our club, as well as pop warner and one of my sons travel baseball teams (yes I'm crazy). All three of my boys (9th, 7th and 5th grade) have been playing football and baseball since they were 5 and started wresting 3 years ago. It's tough from a competitive standpoint to push them to the highest level when other kids are getting more swings in or more mat time or going to various year round football camps. As a parent, at some point, you have to start making tough decisions regarding year round sport activity, not just from a progression standpoint but let's not forget a financial one as well. I've seen many travel baseball players slowly walk away from the sport around the age of 13/14 and its been discussed in great length in the baseball community that part of this reason is because they simply start to lose their passion for the sport. Some of these youth baseball teams are playing 70-90 games during the season, which is insane.
However, wrestling seems to be a sport where only the passionate survive. You can't really force a kid into wrestling as it typically doesn't end well. Because of this, I honestly don't see wrestlers losing their passion as quickly as a baseball player might, not to mention that baseball is probably the biggest self esteem destroying sport out there from a statistic stand point.
College recruiters have also said they prefer multi sport athletes, but that can be misleading, because they aren't recruiting mediocrity either.
The real problem here are parents: Parents have this crazy notion that their son/daughter should always be at the same level as Johnnie down the street. Truth is, Johnnie matured earlier, has better muscle tone and at the age of 13 is done growing. Kids develop at different rates, regardless if they practice year round or not.
Year round wrestling isn't pushing people from the sport, parents are.