Why should I bother? I have many projects on my box, each of them lives in virtualenv, each has it's own packages and all the projects are separated from themse

Why should I bother? I have many projects on my box, each of them lives in virtualenv, each has it's own packages and all the projects are separated from themselves and the system (meaning my global, system-level python can not use any of the packages in virtualenv). So why should tell system pkg manager about something which is not system-wide? Also, virtualenv comes in stdlib now!