Gremlion: And where is the laziness here? What can Crate do there? Realistically?
What can Crate do realistically? It's real simple:
Step 1: Send an email to Steam that says something like this: "Hi Steam. We would like to make our game, Grim Dawn, and its expansion packs, compatible with Crossplay between GOG and Steam. Can you please provide us with the information we will need in order to do that?"
Step: 2: Send an email to GOG that says something like: "Hi GOG, we would like to make our game, Grim Dawn, and its expansion packs, compatible with Crossplay between GOG and Steam. Can you please provide us with the information we will need in order to do that?"
Step 3: Wait one or two business days until both companies respond, then read their emails and acquire the knowledge in them.
Step 4: Spend a few hours writing code changes into the game that will incorporate the knowledge from the emails.
Step 5: Copy & paste those code changes into the next patch.
Step 6: Publicly announce that GOG users can rejoice because Crossplay now works and therefore they are no longer being shafted with versions of products which are sub-par in comparison to the Steam versions of the exact same products.
Maybe the process of how it could actually happen in real life is a bit different than that, but it should be a pretty good approximation. The point is, it can happen if Crate bothers to do the small amount of work necessary to make it happen.
And if for some reason that is not the case, then
the very least Crate can do is to give a public statement that fully discloses all the efforts they've made to try and make Crossplay work, and why they were unable to do so. Otherwise, it's a fair presumption that Crossplay isn't there simply because they can't be bothered.