Not to mention that the majority of bucks will never reach "trophy" size no matter how long you let them grow. That's one of the things that makes large bucks so special, they are rare under any circumstance. This isn't sheep hunting where we can age an animal on the hoof and know if we're looking at 6 yr old full curl vs an 8 yr old full curl.
There are many units throughout the west with very restrictive tag allocations that still don't have giant bucks behind every tree. I see the posts in the forum every year. "Unit X isn't what it uses to be ...", "I hunted 10 days and never saw a buck over 140 inches, not what I expected for hunt with 2% draw odds" Presumably these are hunts where most people are "letting them grow" and big bucks are still hard to find.
Go back and listen to this:
Robby host's Kevin Monteith. They are busting up the myths surrounding age of buck or bull vs. antler size. This episode will surprise more than a few hunters.
www.rokslide.com
On another rokcast I think it was the Utah biologist that mentioned that they age all their bucks and have killed many older age class bucks that did not get very big.
Here is another example (whitetail) but based on the sources above I would bet mule deer are similar. Look at the difference between the 9.5 yr old buck and the 3.5 year old buck. If you saw the two side by side would you pass on the 9.5 yr old deer to let him grow? What about the 3.5 yr old deer that actually has time and room to grow, would you pass on him? Back to the sheep example, would you pass on a legal full curl 6 yr old ram because you knew he was young and has time to grow into something truly special?
Now that year 1 of the north-Idaho deer aging study results are back from the lab, we were able to analyze some of the results and provide a short summary for you to enjoy! Take a peek at this write-up & video!
idfg.idaho.gov
As far back as we have kept harvest records, young deer, forkies and 3-pts have made up the majority of the harvest. I think we have idolized big deer too much and as a result we have to make excuses for why we don't kill a 180 buck every year. It's easier to blame others shooting forkies than it is to find big deer.