Also it's the only way, because DLC has inherent store binding (whereas earlier expansion sets didn't have it).
Which expansion sets do you mean? In GOG, retail, or what?
No, just expansions sets like in former years. The classical way, you know? ;) Buying a disc, then buying another disc with the expansion set some months later. Today they are called DLCs (even if it does not necessarily mean to be a full expansion, but expansions come as DLCs …)
1. GOG starts selling newer games with DLC, both DRM-free, but the DLC has store binding, i.e. you can only use it with the base version of the game bought from GOG. This is already the same thing other stores like Steam do: if you want to buy and use a DLC from Steam, you need to have bought the base game also on Steam.
So in my eyes, you can
replace DRM by DLC and it goes the same way.
That doesn't really have anything to do with the DRM, it just means the Steam and GOG versions of the game are incompatible with each other. Just like many US and EU versions of retail PC games were incompatible, ie. you couldn't use EU updates or expansion packs on the US version, and vice versa.
That is correct, but it doesn’t change my statement: it is a store binding. In times before downloading games (AKA buying CDs) you could buy the base game in one store and the expansions in other stores. No store ever checked if you have bought the base game also there. Of course you are right, you need to have the same version, but who in Europe would buy an expansion for the US version? That’s a silly argument.
Now we have DLCs with store binding (or vendor-lockin, name it as you want). I admit that this is not quite the case, because GOG’s DLC is only a DLC for the non-DRM version of the base game, but since GOG is the only store selling these, it’s a de facto store binding, no matter how you look at it. Steam does it, Origin does it, now GOG does it, too. The same customer-annoying business model. That’s quite sad.
I mean, GOG didn’t want DRM, they stood against the big publishers when starting to release newer games. They made a point. Result? We have a growing number of quite good and new games without DRM. Very fine. :) I hope they will do so in similar way with DLCs, so that in some years we don’t have they same (crappy) DLC business model with vendor-lockin as now also on GOG, but a different, a better one.
How should this better one look like? I don’t know, that is up to GOG. But for me this DLC practice has many disadvantage, and I don’t want to be tightened to a specific store, even if it’s so a nice one like GOG. For instance when I bought a game on Steam, because there was a sale or even because it was not being sold here and I wanted to play it. Then some months later it is sold on GOG, a DLC comes out, and GOG has a sale for it. Now I can’t use it. I need to buy the DLC on Steam if I’m interested.
The other way round it works the same way. No offense to both stores, they want to make (more) money with this DLC store binding strategy. It’s just not quite fair to the customer, not as fair as years ago, in the disc age.