I feel that the more people play the more they are going to accumulate home rules, either based on the DMs preferences, the groups preferences, the nature of a specific campaign, and most likely a combination of all the above.
I would be interested in knowing how many new GMs start with home rules versus trying to stick to RAW or experienced GMs starting with a new system, do you try to stick to RAW for a while?
My preference is to initially stick to RAW and really learn the system. Even then, I do find that I tend to jump into home rules that I latter determine to have balance issues. Well, "balance" is the wrong word. I'm not THAT concerned about balance, but sometimes what seem like minor tweaks can have really change the nature of play.
My current campaign has been running a few years. When it wraps up, I'm thinking of running a few mini campaigns so that I can explore more rule variants and play styles.