This reflects that more resources are needed, not that GET needs to be discouraged. High GET rates should (in my opinion) have no impact on the cost of PUTs. Potential misconceptions of the SAFE economy are just my opinions (ie not any sort of agreed facts or planned design or coded implementation) but to me it makes intuitive sense that a) storecost is only used to rate limit uploading when needed b) reward is only used to bring in more resources when needed and c) membership rules ensure permanence of data.
Point b) is related to high GET rates, and as GETs increase it’s the reward lever that is needed, not the storecost lever.
Hope this helps you understand a little more about the possible mechanisms.