I was thinking that they purposely dropped raster lighting with RT off so that RT had a chance of at least being semi playable, I am assuming that with RT on it would be applying it over already rendered in things through rasterization so it makes sense to me to cull some effects with no RT.
The trade off is a very crappy looking base game without RT though.
Heck I even think Dyling Light 1 looks better than this without RT, the aesthetic works in the first game.
The game looked better in some ways when it was first announced. Little too much volumetric fog, but overall it was better