An all-fridge certainly exists, I was just commenting that they aren't common. Yes you found one at what sounds like a local store, but at Lowe's/HD/Sears, etc, maybe they have 1 to choose from out of a few dozen fridges. All this means you are way less likely to find one on CL. If I go search chest freezer right now on Denver CL, I'd expect no less than a dozen results. Just trying to be realistic for someone looking for one. Not everyone jumping into fermenting or kegging wants to drop almost a grand on an appliance. I've had 3 chest freezers in my 10 year brewing history and never spent more than $50, and I even made money on one; they are very easy to sell if you don't permanently modify it.
Have you ever lifted kegs into a chest freezer? I would say putting kegs in my fridge was far from easy. Like I said, you are crouching/bending over since you have to go horizontally into a low space. That is much more difficult than standing and lifting something straight up high (since, conveniently, the keg handles are right at the height of most peoples' hands, so there is no bending over at all). Set it on the freezer lip, then lower it back straight down. As you said, as soon as you make a second shelf to fit more than 4-5 kegs, you are lifting kegs now even higher than a chest freezer. You also need a shelf that can hold 250 lbs. I can see where an older person, short person, or a female might struggle to lift the 50lb keg 30" to a chest freezer lip, but a male in his 20s/30s/40s, what is that.. 97% of the people on here?

50lbs bit not THAT heavy.
1/4 barrel?? Don't even ask how hard that is to get on the bottom shelf of a fridge! It sucks. But throwing it in a chest freezer is a breeze.
Also, head room. Kegs in a chest freezer with open lid has wide open head room to work with your hoses, qds, tapping sankes, adding/removing/moving kegs around, etc. If you have two rows of kegs in an all fridge, (Or kegs in a normal fridge), the head space is fairly limited, and I just get frustrated easily, trying to hook up stuff, move hoses around, reaching to the back to deal with those kegs, etc, again, all while kneeling or crouching.
In a chest freezer, I can remove any keg without disturbing the others, tend to leaks or change fittings/qds, remove beer hoses for cleaning, etc all while standing. If you have 5 kegs in a fridge and a back one kicks?? Not fun.
I agree, use what works best for you. But someone just getting into this may not think of these things, so they don't know what works for them. I've done both, so I have a good idea of the pros and cons of both and just trying to educate someone trying to decide. Like I said I def. have my eye out for an all fridge for my morebeer conical. They are perfect for that. But I have a feeling, due to price, I'll end up with an upright freezer. I've never seen an upright all fridge on CL.