I agree that there should of been a SP campaign. I actually liked BF campaigns but a lot of peeps didn't.
But I don't agree the comparison between BF and Titanfall. It wasn't the lack of campaign that hurt Titanfall, it was that there wasn't much to the MP. It didn't have any lasting value. Basically, if Titanfall was an extensive SP game (and I would be totally interested in that), the MP would still be empty a year later.
Also, best comparison is BF1942. The grand daddy, which didn't have any SP at all. Battlefront has missions and stuff but BF1942, you could play MP with bots (which were incredibly dumb). It did well considering....and nobody had issues with the idea of getting a MP only game.