I agree, and that is the problem with the argument that "some exotics everyone shouldn't have." If this argument is true, then the exotics "everyone" can have (The Truth, Plan C, Suros, NLB, DB, MIDA), should not be exotics. They should be vendor items since "everyone" can buy them (just with coins instead of marks). Or if this argument is true, the exotics "everyone shouldn't have" should not be exotics at all and be some higher level of weapons (ie epic). Doing this would obviously remove them from Xur's inventory and only be available through RNG. Otherwise, if these "not for the masses" exotics are still exotics, Xur should sell them too, and not from what I have heard weight them differently so that they never or rarely pop up for sale.