Honestly, I think much of it is "urban legend". I've "faked-out" many guests, by telling them beef is venison, and visa-versa. Many just swear they can taste it. I guess its like a venison placebo test.
When I was in college in the mid 80s, my freshman psycho class, did the "Pepsi challenge test" to a group of 50 contestants. We compared Coke,Shasta, Pepsi, and RCCola.
At the end of the test, people were darn near fist fighting, arguing,
cussing, threatning. You see it was ALL Pepsi. Coke won though! Never trust a psychologist.
In chilli, spaghetti, venison-burger helper, etc., ground venison should be indistinguishable. With the possilbe exception of the texture in some dishes.
It's all in the prep as they say.
I know I have had some deer that was prepared for me, that was just metallic tasting and bland, and just plain gross.
Iron most likely, as mentioned above. Lack of fat too.
Too often, temperature is misused in cooking, and the art of larding is misunderstood, with such a lean meat.
Just throwing a plain deer roast in the oven at 375F for awhile is
a sure fired way to ruin everyone's first experience.
If a piece of meat is tough and stringy, you will have to taste the cooks poor prep more and more as you grind through his dish.
Ive read dozens of times, that a wounded deer or stressed deer, will instantly be unedible and have a foul taste. I have just never found that to be the case.
And I have put down some seriously wounded ,stressed deers, often days after they were shot, or hit by a car.
As morbid as it may sound, I have also recovered a downed deer, the following day. Some 12+hours later with good cooking success.
Although, I elect to leave meat in the chest cavity(most heat) alone.
Even in very cold temps.
I have also read, that any deer urine spilled on the meat INSTANTLY renders that meat ruined for flavor.
Of course I don't want to spill any, but if spilled, just wash it with the hose asap.
Trial and error.
Prepared properly:
Fascia, and fat removed.
Meat washed well
Bled properly, possibly soaked,
Aged as much as allowed.
Larded (bacon for example)
seasoned properly
cooked slow...
Delicious.