You do understand that pre-order DLC/bonuses are the bonus for buying the game full price, right? There's a fairly big 2nd hand games market that gives £0 to publishers/devs, so there's a move to reward people who buy new copies.
Yes, of course I'm aware of that. I guess the difference between rewarding pre-order customers and punishing non-pre-order customers mainly lies in being a developer/publisher and a customer, respectively. Like I said, I'll certainly wait and see how this turns out and will most likely even pre-order CK2 because, up to now Paradox, as a company, didn't disappoint me and the game looks very promising. Still, as I see it, buying a game later, especially if you still pay the full release price for the basic game, shouldn't be a reason to pay more for the same product.
Pardon the exaggerated example, as I know it's not exactly the same, but when Mercedes said the first 1000 customers of the new E-Class will get the the brakes for free, the rest has to pay extra doesn't seem right somehow. If they, on the other hand, said the first 1000 customers got a exclusive sticker which reads "I'm a real Mercedes freak" no one else got, I'd say that's perfectly alright.
The problem with the second hand market is rather that the one selling the game, most likely, will still be able to play it illegally. Otherwise, you sold one copy and one person is using it, so nothing is wrong with reselling, I'd say. But that's more of a matter of piracy and digital/physical products in general, but that's not really point of the discussion here, so I won't to go there.
But I always thought Paradox games wouldn't have much of a problem with that, as it's usually games you play on and off for months or years in contrast to finishing a campaign and maybe dust off the game a few years later when feel like it, which is the case with e.g. most non-MP-focused shooters or adventure games or games with a movie like/story heavy presentation in general. Sure, the already mentioned "wait a year or two and buy it cheaper and complete" mentality sure exists, but I guess the modular expansions coupled with the more frequent patches actually could be a good model to fight that. Still doesn't excuse day one DLC, but then again, we'll probably have to agree to disagree on that.