Installing and deleting software is not related to the daily use of the computer. It is related to the administration of the system. It also is not something you do several times every day. The Gnome Developpers therefore opted it wise to keep these aspects out of the interface in which you do your daily work. An added benefit is that inexperienced users then will not inadvertently delete software and require help desk assistance because of this.
This could be implemented by a Gnome Shell extension. Possibly, nobody took interest for the reasons mentioned above. You could file an enhancement request to the developers of Gnome Shell, but I feel that the chances that that would be accepted, are very small, for the reasons stated above.
Your options to remove software are 1) using the software center 2) using synaptic package manager or 3) use apt remove
on the terminal.