Publishers don't mind games made with construct 2, but you do have to respect a certain set of guidelines. The developer has to offer a game that runs smoothly, that is above a certain quality threshold (close to licensed flash games nowadays), and that offers a good user experience over many devices. Basically as a dev, you just have to provide the publisher with a solid finished product, served on a plate, and they won't even check whether it has been made with c2 or not.
We've successfully sold quite a few exclusive and non-exclusive licenses for c2 games with my teammate.