1) This is NOT Battlefront 3
I think this needs to be said right off that bat. Battlefront 2 is a decade old game that while great is past outdated. DICE basically has to completely start over at the drawing board here, so going in with the mindset that this is a direct follow-up to BF2 is already setting yourself up for disapointment.
2) Battlefront never had a real campaign
Why people would complain about BF not having a campaign is so nonsensical that it borders on being a parody of the gaming population. The "Campaign" in the previous BF's was the most tacked on SP I have ever seen. It was Instant Action with a different name. Furthermore they have already said there will be a bot mode, and even if there wasn't it is no longer really necessary. The PS2 era lacked ubiquitous online capabilites but it is 2015 and we can play together now. I feel like a lot of the disapointment is from Star Wars fans who just want another great SW SP game. We all do, but Battlefront isn't that game. I'm sorry.
Ya these two points completely contradict themselves. Your telling people this isn't the same Battlefront we once knew so don't expect it to be the same DICE had to start all over, oh but that doesn't mean they will add a SP mode its still Battlefront!