I don't understand, why are they being suckered? What part of the deal is kept hidden from them?
You need to stop this atitude of thinking you are above everyone else, if they think ALL the dlc plus 5 days early access is worth it, fine. If they don't, don't buy it.
If they were being kept oblivious of that or it they broke their part of the deal, like shipping extra DLC not included, then yes they are being suckered. Otherwise, again it is what it is, and this applies to game pass games or not.
I know iRacing well, I was subscribed for a year, then decided it wasn't worth it, since I have more fun with vanilla AC, but man they never keep this hidden from you. Like if you choose to keep paying for cars and tracks that's on you, yes the "free" selection is terrible I only played Formula Vee and it's worse when you start climbing the SR, but again that's never hidden from you.
I'm not that hardcore of a sim racer but there's a reason people are still on it, to it's credit it was the place where I had the cleanest races and most admin "presence" (in reports), every track is laser scanned and every car is, yes you "lose them" the you stop subbing but again, that's never kept hidden from you. Any MMO works like this.
But to pull it back to GP, at least you have the option to buy the game at any point, in the context of the industry it's really not that big of a deal. With iRacing or WoW, you don't really have that option. With games that remove the content like Destiny you don't have that option. With games that shutdown their online services and make you purchase moot, you don't have that option. And plenty more.
At that point I'll probably unsubscribe or will not pay for DLC I know I can't "own" with a base game in the future, but until then you got look in the present. If you don't think it's worth don't buy it, but no one is being "suckered".