Trossie,
Apologies for the mis-spelled name, my iPad autocorrects it to Troissie for some reason.
Your quote is incomplete. If I remember correctly, and this is off the top of my head, 4444 6.7.3.3 then goes on to say that independent ops should be suspended when weather such as windshear or thunderstorm activity are being experienced, but that the types of weather should be as agreed with the national authority.
Such weather conditions would cause any single landing runway operation to increase spacing from the bare radar minimum of 2.5nm, so to portray this as a negative when such weather conditions occur rarely, perhaps 1-2% of the time, is slightly spurious.
DR and Fairdeal, the period between 0600 and 0700 we do land on both, usually alternately for most of that period, but on dependent approaches, i.e. 6nm spacing to each runway staggered by 3nm, so again it is technically incorrect to term the operation as simultaneous.