Oliver does seem to be looking to jump back into the dating pool, so if Arrow hooks up Oliver with Susan Williams in the next couple of episodes, Ritter may want to give Carly Pope a few pointers on what to expect to see from viewers who want Olicity back sooner rather than later.
Olicity has been built as the big romance of the series, and the two nearly got married back in Season 4.
Any actor who came in to play a new love interest to Felicity or Oliver was likely to meet with some opposition from viewers.
Ritter is in kind of a no-win situation in some circles, so most of the dislike will hopefully continue to be directed at Billy rather than the actor.