You must not like fuel injection then - each tube gets its own injector, but there is only one central airflow measuring device ... with carbs, each cylinder gets its own airflow measuring device ...
I've owned a number of "centrally carbed" automobiles (and one centrally injected one), and I've had absolutely no issues with these setups. They work quite reliably and well with zero maintenance, which does not appear to be a strong trait of carbed 911's. Cheap, whatever - if it works, it works. Fuel delivery is a compromise like most other things car related, and I see nothing wrong with giving up the last 5% performance for significantly reduced maintenance and cost if this is deemed important.
Whether a ground up induction system design for a 911 can be executed by a garage mechanic on a budget to meet the desired performance, low maintenance, and cost, is an entirely different issue... I think it might be more difficult than it appears.