Kineticist’s searing flesh damage vs weapons

A Kineticist’s searing flesh ability states the following

Weapons that strike you also take this damage, though the damage is unlikely to penetrate the weapon’s hardness. By accepting 1 point of burn, you can increase this damage by 1 point per 4 kineticist levels you possess until the next time your burn is removed. You can increase the damage in this way up to seven times.

This means that, say by level 12, and by having 7 points of burn you will do 24 damage to a weapon when it hits you. However, this seems to be pointless, as that means that against a measly +1, it will do 0 damage. Is this really the intended effect? Why is this included as part of the ability if it cannot actually damage weapons even less than appropriately leveled at max power?

Or does this imply that the damage is just straight applied vs the weapon without reducing the elemental damage and just must bypass hardness? This seems more inline with balance. a +5 weapon, which is appropriate for martials at that level has 15-20 hardness, and ~60 hp. meaning that damaging it with this ability would do 4-9 damage, and it would have to hit you 4-8 times to gain the broken condition. Which still seems a little fast. but considering your spending 84 hp to sustain, seems relativly balanced as your not likely to survive 4-8 hits from a level appropriate weapon without some other form of defence.

How does this ability actually work against weapons? Is that entire clause pointless or is it actually possible to have it be semi-relevant?