Hmm,
I define damage as deep gouges from moving furniture, stilleto heels, forks pounded into the floor by your toddler, riding / eccessively sliding toys on floor with debris trapped under... Although most people experience this, like crayon on walls, these would be considered damage by me.
From your pictures, I would have expected that you were moving heavy AV equipment on cardboard boxes all the time, or had a child toy like a plastic riding car with stone stuck in the wheel. If it truly was none of that, then the finish did not keep up.
If I were you
1) I would point out that the last refinishing job was sub standard, or intended to be refreshed every few years. Ask a lot of questions, putting the blame on the LL -The coat is pretty thin... how many coats? oil or water based? Did you refrain from walking on it for the first week? etc.
2) Suggest a Screen and recoat is what is needed to restore. (not a sanding, just a buff and top up)
3) A screen and recoat may need to be normally done every 3 years, so if you have lived there for a year, then you would only pay 2/3 of the cost of this... (get a quote for buff and recoat only) e.g. $1500 x 2/3 = $1000 maximum
4) Start talking about -- "look how clean we are leaving this place", "you have had very low costs with us", "we have been a dream tenant about paying on time and bothering you rarely, this is minor compared to what you could have had,... therefore we expect the full deposit back"...
Lastly, if not biting on the above...
Find out what the depreciated value is on 17 year old pre-engineered flooring intended to last 20 years... only 15% of the life cycle value would be left (at best), which is the most that you could be expected to fund, and that is if you extensively damaged it to an unliveable condition (e.g., dog pee stains over 40% of the floor)
Then, take the % of damage -- half the floors? more" and multiply.
e.g.,
20 year life cycle (assumption) - cost of $10,000
3 yr remaining / 20 = 15%
15% x 50% damage amount = 7.5%
7.5% x $10,000 = $750
Refinishing it to rent out was akin to a landlord putting in new cheap white carpeting just before renting to tennants. I don't know what he was thinking, but good luck to you as this does not sound like a LL with any experience in realities.