There's a huge difference between writing open source software that benefits your company and open source software that directly competes with your company's core products. There's plenty of room to find something that wouldn't be a conflict of interest.
This right here is the classic definition of a leech. I am only in favour of open source if i can benefit from it. I am not in favour of the part that suggests that I "contribute back to the community". Well, I guess everyone is in their right to be an asshole. When you smell the stench then you know what's coming :)