Get a 2nd Focal Plane if you are hunting, because I cannot ever remember a time when the quarry stood still long enough for me to calculate the range and then work out which crosshatch to use.
I have the rifle and scope sighted to rise no higher than the vital area and drop no further than the vital area within a set range parameter that:
a) I am comfortable shooting at.
b) That I expect to see my quarry.
So for a fox that means 1.5" high and 1.5" low and a max range close to 300m.
It also means that if I am on a low setting the crosshairs are not invisible and at max setting they don't cover the target.
Use a second focal plane if you are target shooting as you already know the range and have time to dial it up the using the turret.
Use a FFP if you are doing some old fashioned sniping and have to calculate range using your milradians and a knowledge of the height of the average man, the height of a soviet truck's wheels or the length of commonly used bricks and besser blocks. (I have used this on kangaroos as their chin to ear tip is pretty much the same regardless of sex and age. Used to euthanise roos stuck in the mud of a huge tailings dam).
No-one in a modern army does that any more they use laser ranging and self setting scopes.
FFP used to be more robust too as the early models have moving reticles, but that is a thing of the past also, all good scopes are robust now.
WIth respect, I disagree with your logic. Not being able to remember come ups/hash marking is a byproduct of not training/practicing enough, and has nothing to do with the capability of the scope.
As to the second highlighted response; this is completely false. SFP scopes have historically always been more reliable simply because there are less lenses and mechanical components that have to fit inside the scope tube. Only until the past 10 years or so, have FFP scopes come close the ruggedness of a SFP (nevermind a non-variable) scope, though usually at the cost of weight (but there are now many that come close to the weight of SFP scopes).
As to ranging and calculating, that is typically done via a BT enabled pair of LRF binos to either a scope or a Kestrel these days, which spits out the corrections within seconds. Nevermind that if someone trains with a FFP scope, they typically either know their come ups by memory, or have it written down on an armboard (which is just prudent for obvious reasons).
Besides, for hunting, with most modern cartridges, the come ups for a reasonable distance, hunting shot, is usually within 1.5 mils of zero, so you don't have to remember that many come up values for holding with the reticle.
Finally, the main strong point of a FFP scope, especially one with a "Christmas tree" reticle, is that a shooter can reliably and extremely accurately, hold for wind. Even at close ranges, in strong winds, your shot can be pushed off it's mark easily. Being able to hold for wind and elevation makes FFP scopes far superior IMHO for hunting. But you have to understand, practice and train with the tools you intend to hunt with, or you're no better off than the so called "fudd" that thinks minute of paper plate suffices for a zero.
I'm always amazed when people disparage hunting with a FFP scope, when in their comments, it becomes pretty obvious it has nothing to do with the scope, but rather their ignorance or lack skill to utilize a FFP scope with a mil reticle to its full potential. i.e. It has more to do with the shooter, rather than the optic. It is why we have hold over stages in competitions; it forces you to use the reticle as well as gain confidence in the reticle. Which in turn makes the shooter more effective in the real world, where shots need to happen in seconds, not minutes.
There's a reason there has been a huge increase in the purchase and use of FFP scopes for hunting, and it not just because the prices have come down, or that there are many, many more options cost effective these days. It's because (IMHO) more of the shooter community has become educated enough, and train enough, to use a FFP. Because it increases their effectiveness with a rifle.
ETA: The more pertinent question IMHO, is why wouldn't you hunt with a FFP scope; especially when hunting from a high seat or in some type of "overwatch" type position? FFP scopes are tailor made for that type of engagement. Coupled with a range card of the area, with TRP's (Tactical Reference Points), a FFP scope allows a shooter to be extremely fast and effective at sending bullets down range accurately on to a target/animal. Far more accurately than using a simple SFP duplex reticle and holding off "about this much" in windage and elevation.