I can't speak for the OP, but the intent of socialism is to agree on collective programs and processes to spread wealth and access (education, health, etc) across communities. It's not to change peoples personalities. At most, it might reduce some of the reward for greed.
You first have to create the wealth before it can be distributed. Capitalism is the best system of wealth creation. How does social create the wealth that is to be distributed?
Systematic reform is basically the opposite of idealism. If you think you can convince people to be 'less greedy', then it's you who are being idealistic.
Socialism is not a systematic reform. It is a drastic change in economic structure. Not that I am necessarily against it. I just don't understand how it is any better. If it is social programs you want then capitalism can create the wealth to support them.
Socialism tries to eliminate competition, which reduces the motivation for innovation. Innovation creates value which increases the wealth available in the economic system.
I'm not saying people can't be innovative in a socialist system but there is no longer any need for it. If the system stagnates it will have less and less wealth to distribute. Eventually, the wealth runs out.