Solid rocket motors are conceptually simpler, but much more dangerous and in many jurisdictions legally dubious to make yourself compared to hobbyist bi-liquid or hybrid designs.
Off the shelf, solid fuel motors are almost impossible to start accidentally. I don't see how they are more dangerous than dealing with tanks of pressurised gases.
Making solid fuel motors yourself is dangerous (and illegal without a licence in the UK).
Making solid fuel motors yourself is dangerous (and illegal without a licence in the UK).