Some companies are just not that smart, so instead of building a strong relationship with their current consumers and eventually gain new ones, they decide to do a one-time scam and trick people into buying their products. That guarantees the loss of what could've been a loyal consumer.
Packaging designs are really tricky, you can trick people into thinking that they're getting a good deal on something when in the reality you're giving them way less than they're used to getting. It's done so subtly and masterfully that most people can't even tell the difference.
These packaging designs were probably designed by Satan himself because a normal non-diabolical creature cannot possibly come up with something as evil as this.