We've had this exact argument, to the letter, repeatedly. This has been considered in detail, and if you want the reasoning why a proposal for type based access will never be accepted by the core team then read the previous two threads on the matter. [1][2]
Please stop bringing it back up. If you notice the levels of vitriol this subject managed to produce last time, you'll see that I was hardly exaggerating when I said that the whole topic of access control was radioactive.