No online component, no.
As for reasons, price? TW3 is £44 on PS4 via the rainforest. The PC version is a tenner cheaper, or there's the great GoG deal (£36.49 for the digital copy, DRM free, £7.80 back in GoG credit and a bunch of bonus content). Add in the 'bleeding edge gfx', faster updates and the fact that purchases via GoG mean the developer receives more of the money you're paying and it's a no-brainer IMHO.
As for reasons, price? TW3 is £44 on PS4 via the rainforest. The PC version is a tenner cheaper, or there's the great GoG deal (£36.49 for the digital copy, DRM free, £7.80 back in GoG credit and a bunch of bonus content). Add in the 'bleeding edge gfx', faster updates and the fact that purchases via GoG mean the developer receives more of the money you're paying and it's a no-brainer IMHO.