It says about a Tinderbox:
This small container holds flint, fire steel, and tinder (usually dry cloth soaked in light oil) used to kindle a fire. Using it to light a torch—or anything else with abundant, exposed fuel—takes an action. Lighting any other fire takes 1 minute.
So that's the normal method of lighting a torch and general rules about setting fires.
Now with certain fire magic and spells, this little tidbit is added in (emphasis added):
A flammable object hit by this spell ignites if it isn't being worn or carried.
Torches are meant to be carried and if I were lighting one I'd imagine I would be holding it when lighting it (dip it in fuel and light a match). If you couldn't light it while it's carried, I would think they would add something in to say "You must set this item down to light it", which in itself wouldn't make sense. So RAW seems to say that if you are holding a torch (i.e., it is worn or carried) and know some level of fire magic, you couldn't light it.
Am I overthinking this or am I missing something?