HA! This makes me laugh. Rene Russo was horrible in The Thomas Crown Affair, I thought she really ruined the movie with all her "fake" acting. Brosnan was great in that film and in The Tailor of Panama -- he was majorly creepy in 'Tailor' but not a bad actor.He cited both "The Tailor Of Panama" and Brosnan`s remake of "The Thomas Crown Affair" where fellow actors Geoffrey Rush and Rene Russo, "acted him off the screen".
Now Brosnan is not the best actor on the planet, but he's certainly not horrible or poor at it. Besides The Thomas Crown Affair and The Tailor of Panama there's Evelyn, Dante's Peak, The Deceivers, The Lawnmower Man, Laws of Attraction, Live Wire, Raw Heat, Robinson Crusoe, Mrs Doubtfire, Don't Talk to Strangers... oh hell, I'm starting to name too many here. Not all of these movies were great (while some were) and some were poorly made (others not) and he may not have been giving an award winning performance, but he's certainly enjoyable and not unwatchable. I wonder if people watching some of these films are actually judging Brosnan's acting or the quality of the film.
As for your friends comment of him not bringing anything to the Bond Films.... I find that ridiculous and I'm not sure how to respond -- my response might turn into some 20 page essay. So I'll stick with this... if anything he brought the suave agent back to life for a whole new fan base who came to Bond Fandom because of him. And if Brosnan wasn't good at being James Bond there wouldn't be new fans who are now upset that Brosnan is out (and I wonder how many of these fans will not be as passionate about the 007 series now that he is gone). That is the biggest and I think the most important thing that he or any of Bond actor has brought to the role... fans.