The crucial difference
There are ways other than card counting that can give a player the edge in blackjack. However, all of them involve identifying when the player has the advantage. That can be done by hole-carding, sequencing, steering or shuffle-tracking (which involves card counting). There may be other methods of which I am not aware, but they must enable the player to identify advantage situations. These methods require money management in the sense of knowing when to bet enough money in advantage situations relative to your bankroll, calculating an acceptable risk of ruin, and knowing when to either bet small or not at all.
However, the system touted in the linked website from the above post doesn't mention any of these methods. It says you can win with basic strategy and money management. In effect, it is saying that it has a betting strategy that will give you the advantage. Betting strategies alone do not give you an advantage in a negative expectation game. Without knowing when you have the edge, basic strategy and money management will not produce a system which wins in the long run.
Identifying the advantage when you are counting cards is not a degree of hope, it is a certainty. That is no guarantee that you will win at all times. It is no guarantee that every time you identify an advantage situation, the cards that will give you the advantage aren't stuck behind the shuffle card, although in honest games, that will even out over time. It is a guarantee that you will be betting more when you have the edge on the house.
Casinos do the same thing. They devise negative expectation games, that is, games where the house has the overall advantage. That does not mean the house wins every time. There will be individual players who will win big occasionally. What it does mean is that in the end, the casino will win more money than it loses. It doesn't rely on money mangement, it relies on its inherent edge. So do card counters and players who use other methods to identify when they have the edge.