if you will improve the core, you may loose your work, it could be used in other projects.. but users would download your miner cause it receives speed updates first hand.
I don't need users to download my miner to make a profit.
1. I can have a large farm harvest all the profit and push other miners over to different coins.
2. I can sell my faster miner to a bigger farm so they can harvest all the profit.
3. I can sell my optimized sourcecode to the 1% miners.
All 3 options are good for me. 1 & 2 could destroy GPU mining for the small farmers.