Yeah pay to win is a stretch... but not everyone would see it as an advantage either ( I definitely do not for 1)
Some do though (I think it depends on one's play style and how one approaches the game).
I still think this is a medium somehow: Only have 10 slots was a pain for some people. Having 100 can be overkill. I would have thought that the way BO2 did it (10 available, and you can expand to 100 but still can only have 10/game) would be satisfactory... but I remember a lot of threads saying it was totally useless, and people were up in arms having to pay for it (not the same people mind you... which proves you cannot please everyone).
I am personally against micro-DLC that is not free. But my personal views are not the correct views no matter many agree (or disagree) with them, but they suit me fine.
(and for the record, tradition is by no means an excuse to keep doing something. The only reason why people are wishing for 10, is because we always had 10... to say 10 is fine because it has always been that way is not a very good reason... I had any say in it, I would have had more than 10 and had them always available - not trying to be argumentative. Just saying)
And as others have stated, paying for more slots is small beans. What is bad is:
- paying for maps you already paid for (many titles)
- paying for a special edition to get access to maps and games, only to have them handed out for free later (BO2)
- buying elite to get all the maps and then having the maps go on sale for less than Elite costs (MW3)
60 CAC with 6 available in game is a change, not a catastrophe. Having to pay for more if you wish it is annoying, true...but shelling out money and being duped while doing it is a much bigger issue. After going through what we went through (as listed above), I see this as a nail in the coffin...
Or maybe the straw that broke the camel's back...