...The 'fact' is that in the last two rounds of announcements, Silver, Gold, Premium and 'Platinum One' members have all received (somewhat) tangible service improvements. While there hasn't been a significant derogation to Platinum benefits (unlike the last round that took away Anytime Access which some - though, granted, not all - members considered to be quite significant) the net effect of these improvements to the other tiers is to reduce the incentive for Platinum members to maintain their status. Very few will be in the position to leap from 1200 SCs to 3600 SCs, while in the meantime the benefits of sticking to 600 SCs are more attractive. And why wouldn't you, when you get improved benefits for a smaller total spend with QF so long as you fly premium? The rest of your travel spend would simply be better spent on similarly premium (or otherwise) services with QF's competitors.
Take it as you will, but as far as the 'facts' go, QF needs to acknowledge that they have not delivered any improvements for Platinum members as a whole (or better yet, do something about it), while having taken away significant benefits in the past year and improved the position of almost every other tier.