That is a really good intuitive question my friend.

When it comes to cloning with these little net pots, it more about what the pot does for me than for the plant.

The roots will emerge from those holes once they start, and this is the main reason I use them, visual confirmation holes. Saves a little time and effort instead of planting straight into soil. In the event that a clipping doesn't take, it's more work altogether. I'll take pics of the roots emerging from the holes when that time comes!

Net pots are also used in hydroponics, which is where I got the idea for this use.