I found this (replace the XXX's) as the #1 hit for a question.  The answer seemed very "stack exchange" and indeed it was:

http://htmlasks_XXXXXXXXXXXXX.com/why_is_the_ubuntu_software_center_being_replaced_by_gnome_software_in_16_04

https://askubuntu.com/questions/725975/why-is-the-ubuntu-software-center-being-replaced-by-gnome-software

Does SE patrol for such things: is there a reporting mechanism?