I see the packs as a terribly executed good idea.But PD made the prices for the packs ridiculously expensive, and then gave little content to allow the player to earn the credits from their own play time. I've heard (through RoosterTeeth) that this was an incredibly big problem in Forza 5 - where it was nearly impossible to get any sort of good winnings, and it would cost the player a few hundred dollars for just ONE of the most expensive cars in the game…
That's just ridiculous. It isn't as extreme in GT6, but 50 mil. credits should be no more than 5$, honestly. It should be the equivalent of a time-savers pack for other games. Burnout Paradise has a pack like this where it unlocks all of the content - efficiently priced at 5$. The problem is, Burnout has proper content to keep the player interested - hundreds of races and events, unlockables, hidden items, massive open world, and all sorts of accolades and achievements to show off.
Trouble is, GT hardly even competes with the "hundreds of races" statistic when it comes to single-player content. From what I've heard, the career is massively short, so you're left grinding and repeating old events. Then the payouts aren't massive, so you're also forced to waste time just to get to some preferred content. In terms of game structure, it should start with low-payouts at the beginning, and then massive, potentially multi-miillion payouts towards the end. You shouldn't need to rely on purchasing in-game money to play the game you've already payed for, that's just wrong.
But there is a use for these packs, as long as they're well-executed;
Let's say you're a strictly online player, you have the experience from past sim games, and you really don't want to play the single player to get the content in the game. You can just throw down a few bucks (or even cents at this rate) and you get enough in-game cash for a good bunch of cars, and you're free to go online from there. Then you can rely on online race winnings. And at that rate, you'd have the potential foundation for live online seasonal events, so you'd almost have an online "career" mode available… But now I'm just dreaming.
*Edit: Basically, this pack should allow you to skip a major portion of the game for a very low price - and it is doing neither of those things right now. The career isn't long, and doesn't produce much in-game cash. And then you pay half the game for some cash that doesn't amount to the price of quite a few single cars in the game.