This is like saying "burning gasoline produces CO2, how do you make energy with that?" Literally the quoted energy they use to calculate the ignition criterion for NIF is the neutron yield.
When I first learned how nuclear reactors actually generate power it was a big WTF moment for me. Wait - do they really just heat water? For some reason I thought that there was a more advanced process to extract electricity from the reactor.
In Back to The Future, Doc Brown not only invented a time machine, but a device that fits into a Delorean that can directly convert plutonium into electricity.
That literally is it, just like fission you capture neutrons and heat water. The engineering issue of getting a stream of pellets to shoot is the issue, the "how do you convert neutrons from DT into electricity" just betrays severe ignorance. The engineering issue is a bigger jump.
The issue of capturing power out of the exploding pellet is not at all the same as the issue of capturing neutrons out of a MCF reactor, and neither is the same as the problem of capturing the neutrons from a fission power plant.
The neutrons from fusion reactos are far more powerful, so they punch much more easily through materials you put in the way. Also, the ICF reactor has many moving parts (the pellet needs to be put in a very precise position for the lasers to shoot), so transferring heat from it is not nearly as easy as a much simpler fission reactor (which is mostly just a hunk of uranium which stays hot, and all the complexity comes out of being able to prevent the uranium from getting too hot).
