I understand your frustration, but it all comes down to what the Code of Points considers good execution.
You see, in every skill we have to consider how cleanly it's performed in the air (legs glued together, toes pointed, clear body position in the air, great height and amplitude) and how well it is landed. One small step or small hop deducts -0.1, a medium/big step or hop deducts -0.3.
Yeo had the hardest vault of the competition, worth 6.2, and she needs massive speed and air time to get it fully rotated, which she does. The deductions on landing, apart from steps and hops, also consider deep landings (up to -0.5 in deductions), but her landing was not that deep and probably avoided a bigger deduction. If the gymnast lands with her chest down, the deductions could be -0.1, -0.3 or -0.5. Moreno unfortunately loses -0.3 to -0.5 due to her low chest position. Her form in the air is also not as tidy as Yeo's, and her vaults are not that high. Deductions for the height of the vault can be massive, up to -0.8!
There are lots of things to be balanced. That's why I mentioned that Zapata has poor execution, despite great landings today, because his body shape and leg positions are usually not good. Even so, he lost little to no tenths on landings and got a medal. Dolgopyat has much cleaner body shape in the air and even though some of his landings were not great, he still managed to lose as little as 0.1 in landings.
Take Andrade for example: she only loses 0.2 (0.1 for each hop) on the landing of her second vault. It doesn't look good for us, of course, and one can imagine she will be deducted a lot more, but the Code of Points only allows for a 0.2 deduction (plus small 0.1 deductions for things like deviation from a straight line and so on). When it comes to the more hefty deductions like height and dynamics of the vault, Skinner loses a lot while Andrade loses very little. This is also the same for Yeo and Moreno.