It was the mid 90s; the dawn of the web. For the first time ever, THE PEOPLE had access to create and share media across the globe. I was in high school at time and used the limited features of HTML to makes games where you click on celebrities to make them die in all sorts of horrible and comical ways.
Then Flash came along, originally made for interactive media vs outright games, not even having support for variables. Clicking buttons to make animations play was one of the only things you could do. Shooting galleries were a natural outcome, since they require clicking things to make stuff happen.
Celebrities and pop culture were an easy target because they represented the establishment and the web had lifted the barrier for the rest of us. Many of these games haven't aged well but they were a fun way to blow off steam back then.
Unfortunately most of my early Assassin games were deleted when the 2012 site redesign launched and a bunch of old files were cleared out. My original games had never been part of the Portal system so they were easy to overlook.