I would sell that it's a privilege to have a job where you can think about things like deep mathematics and still do something that's useful for a possible application. This can appeal to people who vary from the small academic people who just want to play with stuff to people who actually want to change the world.
A lot of today's youth want to change the world, so it is critical to explain how quantum can change the world as part of the pitch. A lot of people are interested in energy for very good reasons, but quantum can change the world just as much as developing solar cell material can change the world. You can use a quantum computer to design solar cell material and you can use quantum spectroscopy to study energy materials.
It is really important to appeal to all of the different aspects that motivate people to go into a field. Changing the world and doing cool science covers it.