Mining is not what that should be regarded as a hobby. Or I can not condoir as a hobby. The reason for this is because I do not think someone will say he is mining bitcoifir pleasure. Hobbies are activities that you do for pleasure. Those that run nodes that are rewarded without nothing are doing it for a reason also, like they want bitcoin network to be more decentralized or they want privacy. Even if some people just like to be a miner and not benefiifrom it, it is still not a hobby for such person because no pleasure derived from it.