I would also like to point out that in 4th edition (if I'm recalling correctly) they actually had it set up such that if you tried to use Cyberlimb Strength/Agility enhancements that were too strong (higher than 2) you had to have a Cybertorso. Now, that rule was only for the Enhancements, the ones that take up capacity, but it was an interesting concept.
That was only for Standard, not Customized limbs. From SR4A page 343:
"On standard cyberlimbs, a cybertorso is required to have cyberlimb enhancements with a rating higher than 3."
Keep in mind that in 4th Edition, enhancements went as high as Rating 7 whereas in SR5 they only go to Rating 3. Customized limbs could go up to "the character's natural attribute maximum)", with each attribute point raised above 3 increasing the availability by 1 and cost by 1,500¥, quite a lot less expensive than the 5,000¥ per rating of SR5. A human has a limit in both editions of 9; in 4th this was due to the maximum augmented attribute value being 6 * 1.5 as per page 68 (which could be achieved with a standard limb with 6 rating points worth of enhancements), in 5th this is due to the max customized attribute of a limb being 6 (i.e. racial max) and the max rating of enhancements being 3.
So really, the two editions changed the rules a little bit, but for limbs the end result is mostly the same for humans; metahumans, trolls in particular, are the exception, where a troll could have a strength 15 cyberlimb in SR4 but "only" a strength 13 cyberlimb in SR5. And, as pointed out above, the customized limbs got a lot more expensive in SR5. A Troll arm with STR 10 would cost 15,000¥ base + either 1500*7 for max versatility (i.e no capacity use) or 250*7 if you didn't care about capacity and didn't want to be able to further enhance it, giving a range of 16.750¥ to 25,500¥; that same limb in SR5 would cost the same base but an additional 5000*7 because enhancements went from 250¥ per Strength rating to 6,500¥, for a minimum price of 50,000¥. In other words, forget about using cyberlimbs if you're a troll focused on strength...
All of that being said, I personally like the idea of a customized cyberlimb being limited by your natural attributes. Thus, a Strength 1 Agility 1 character can only have a Strength 4 Agility 4 arm; this could be circumvented with a cyber torso as per the standard limb rules from SR4 so a STR/AGI 1 character could have a cyber torso with STR/AGI 6 and thus mount arms with STR/AGI 6 + 3 from enhancements for a total of 9. But, this gets overly complicated quickly and brings in the cost issue; in order for this to be viable the cost of limbs and torsos would have to go down, in my opinion, otherwise you're just making a system where things like muscle replacements are even more common, not less.
My biggest pet peeve about cyberlimbs is that a troll gets the same standard arm that a human does, starting out at STR/AGI 3. That's bogus, but again, would require a bottom-up rework of the limb system to make sense. The easiest house rule we've come up with is to allow limbs to affect natural limits regardless of how many limbs you've got, by averaging out the attributes used to calculate the limit. Thus, the character has one limit for using just the limb (limb attributes only), one limit for using the limb in concert with other limbs (averaged across two arms for the most part), and one limit for when the whole body is used (averaged attributes across four limbs plus torso). We've also considered giving the torso more capacity to account for the potential need for enhancements, but haven't settled on a final number (15 and 20 were topics of discussion).
TL;DR
Cyberlimbs are too expensive for what they do in SR5; dramatically lowered cost might help offset the downsides (such as no inherent limit modification) but that could still leave a lot to be desired.