The 32bit version is available for convenience, nobody uses it in prod. You can't complain that a simple testing tool limited to 2gb can't store more than 2gb.
You used a dev version of a tool that is not meant to be ran in production or for any serious task and then complained it didn't work with your attempt. As this bug is not present in the real prod version of mongodb, it doesn't make sense to criticize mongodb for it. Also next time RTFM before using a tool you don't know much about.