I'm fortunate enough to be able to afford all the games I want and it's DLC. That said, I believe all DLC is a cash grab whether or not it is in service to the consumers.
Honestly, used games sales is the one to blame for this era downloadable content. It's to make you keep your game longer so you don't sell your game back. It also cushions the lost sales they get from used game purchases. I think its a fair trade to Capcom and the devs to get what they deserve.
If you don't like it, don't buy it. If you feel like you're missing out on the narrative, its ok, the game isn't even RE canon.