The main point of this meme was to mock WBC's protesting tactics in an amusing and satirical manner. I didn't know that Phelps was the church's leader, or what kind of person he was outside of the church. They've been known as a hate group, and I don't condone their actions.
(According to Wikipedia, he died in March 2014, and this meme was made April 2016, so theoretically anything the church did after his death shouldn't be associated with him...js)