I agree that content generation has it's value via the attraction of more people to the network. However social media apps built on top of the chain serve mostly as fancy faucets for content creators.
The Steem blockchain can be much more than blogging and social apps (steemmonsters is an example that comes to mind). I just think that giving more than 50% of the inflation to the group that least contributes to creating direct demand for the coin is not sustainable in the long run. To me around 40% would be a good number.
The current 75/25 distribution between authors and curators is mis-aligned. The later group takes all the risk of locking up their investment and should receive a higher portion of the reward pool.
Most current users are not aware that it used to be 50/50. The proposal from blocktrades would leave the distribution of the reward pool at around 64/36. Overall authors would receive 46% of the total inflation instead of the 55%-56% that they get today.