SFP scopes like this already exist and are perfect for a good many applications. FFP versions of these same scope work for different users and different application, and there is a place for those too.
I do not need to advocate for SFP scope like this because there is a ton of them.
There aren't many FFP ones, but the simple fact that SWFA 3-9x42FFP is doing great for all these years and a significant part of its customer base is hunters, suggests that there is a market there.
The most obvious reason is that with a 40mm objective, you are not always going to be on 10x and it is nice to use the scope on 6x or thereabouts as light gets a little more critical.
Then, with illuminated reticles, there is a different school of thought out there: one of the advantages of FFP is that you can design a reticle that becomes very unobtrusive on low power, so that you can illuminate a center dot making it really stand out.
For me, personally, I like to practice with my hunting rifle for a variety of shots, frequently the shots that are MUCH longer than I would ever take in the field. Those are much easier with FFP scopes and, given a choice, I would prefer to use the same rifle and the same scope for both practice and field use. That helps with gear famliarity and trigger time.
ILya