It wasn't really "removed" on purpose. The only reason /suicide no longer exists on Infection is because the new plug-in Infection currently runs on does not have /suicide included. As for the first time /suicide was messed up and the colin ":" was need to execute the command was due to the crash Infection suffered sometime in the spring of 2015 which broke Infection greatly (Maps disappeared, most people got reset, etc), and I believe is a main reason as to why Cyp/Crew got a new plug-in for Infection. As for it being added back in, I think it would be quite beneficial for Infection if it was added back in. It would be an easy way to reduce the amount of level wasting. Though there is usually always someway for the last human alive to die such as letting zombies kill you, jump off the map or into lava. But /suicide is just more convenient and less time consuming ([Micro] Seconds wise).
