It depends on the pepper, some are full of seeds and some are very easy to de-seed. Usually with any large annuum like Numex/Anaheims or poblano/ancho etc. it is easy to remove the many seeds and it makes a much better powder. With the super-hots, its just about impossible to remove the seeds without removing some placental tissue so you're removing some heat but you're also removing needless filler that on its own is quite bitter. If it was an easy task, I'd probably always remove seeds but its just simpler to grind most whole