• We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.
no-sense.

STEAM is forcing everyone to buy the game and all expansions on their platform for an obvious reason.

The publisher doesn't care if you buy retail copy or digital copy from anywhere on the planet - the money is theirs. But VALVE DO CARE if you buy the game, you have to buy all expansions on the same platform.

Ofcourse having or not steam is a decision of the publisher, but instead you have steam achievements and multiplayer...

Gamersgate, for example is not forcing anyone to buy all parts of the game in their shop. Ive bought retail copy of EU3 complete and then HTTT on Gamersgate and there were no problem with installation. With steam it's unthinkable.
 
I buy games at Steam only if they are not available at Gamersgate, Impulse or Direct2drive. All are preferrable. Also, I bought KA on Gamersgate, along with Saxons and druids and they don't even work with each other at the moment. But King Arthur is definitely available there.
 
Well, it says "Game: Not prices" and "Game not available in your region" (=Germany). So it's not possible for me to buy King Arthur at Gamersgate
If you live in Germany the only way to play King Arthur is by using Steam:

1) Buying the retail version and unlocking it at Steam or
2) directly buying it at Steam

I did the second one. I also prefer to buy all Paradox related games (and its expansions) on Gamersgate. But for King Arthur, Lead&Gold and Magicka I had no other choice.