The way you’re wording it in the original message, you want diminishing returns on SP injections to be toned down or lifted for older characters, like yourself. Which means, provided that you are planning to inject a particular number of SP, that you will be able to inject the same number of SP for less money. That is a freebie.
I’m not in a position to tell CCP how to run their business, and I understand that discounts and bonuses are a valid tool for both attracting and retaining customers. However, in a competitive sandbox game, these have to be used very carefully and sparingly.
You, on the contrary - again, the way you’re wording it in your original message - want to change the landscape of the SP economy and discriminate against one category of players (with new characters) in favour of another (with old characters) just for your minute personal gain.
Whale A is an EVE player who started in 2009, played for some time and then moved on with his life. Whale B is a player who only joined recently.
One day, Whale A and Whale B thought it would be a good idea to play some EVE and fly a carrier. Provided that neither of them has yet trained the bulk of the skills required to optimally fly a carrier, they have to shell oit more or less the same amont of cash to inject them, as of today.
The way you’re proposing, Whale A is going to get a large discount on injecting into that carrier for no merit other than having joined the game earlier.
In this example, Whale A and Whale B have a roughly equal value for CCP - they both are willing to pay a certain amount of cash for skill injectors. However, giving Whale A a free advantage has an inherent risk of pissing off Whale B and putting him off his purchase.
Additionally, a whole bunch of old characters will gain additional value, even if they weren’t trained at all for their entire life - again, completely for free.