Please understand I am not criticizing you at all but will give you the straight genetic facts from biologist research.
Up front disclaimer: A deer that starts as a spike will never be as big as a deer that starts off as a 3-4pt (nutrition/health considered equal). However, a deer that starts as a spike can grow to be a 140+ trophy deer.
1. What is the age of the deer?
In the picture he doesn't look older than 3 1/2. It is proven that deer do not reach their rack and body maturity until at minimum 4 1/2 yrs and start to go downhill at 6 1/2. And you would be amazed at the jump a deers rack can take from one year to another. I have personally seen a button buck go to a mainfram 8pt with a 16" inside spread in one year.
2. Do you have the sheds from that deer for the past years?
If you have just seen this buck and have no antler record of him then maybe he fell on hard times this year and actually had much better potential for next year. Maybe lack of right type of food, sickness or something hit this deer.
3. Do you harvest the smaller does in the area?
As much as we all love to say the bucks decide what the young will be, you have to remember basic biology and say that its 50/50. Your larger bodied, more mature does will lead to better offspring. So if you are concerned about the young, you need to take both bucks you don't want along with does. On the flip side, if your population is too high, you need to harvest more of your older does because as does age they become more success in reproduction (older does can have up to 4+ fawns while younger ones average 1-2).
4. What types of racks do you like?
I for one don't cull bucks because I don't like a standard rack look. I HATE when you see these ranches and all the bucks are the same, mainframe 8s, 10s, and 12s. I like the palmated racks and odd points and bucks like these (especially if he was only 2-3 1/2) could have bred some really neat racked/monster young. Combined with the right DNA from a doe and nutrition these deer could be great trophies.
5. What is the deer density of the area?
The number of deer you have in an area can actually affect the rack size. If your area is over carry capacity, there is less food for even the best genetic bucks and they can have poor racks for a few years.
6. You can never be sure which bucks are doing the most breeding.
Research is conflicting saying that more mature bucks breed more does, while other research shows that more mature bucks actaully breed less because their movements have become very restricted (wise and old and doesn't take many chances;even for a chance at a woman lol).
Take away point I would stress is that managing for big bucks often means that you need to harvest more does. The way to achieve large bucks is (happens as a by-product) making sure you have a balanced sex ratio along with age ratio.
Hope this helps future decisions on management of deer herds. And good shot/kill on your buck