And being real - ToA temples never become 1000 years old, even if it looks like they have been around longer.
This is what has always irritated me about this Wonder.
It's the most expensive AA Wonder bar the library, and yet its effect is so utterly fleeting. If you're efficient it lasts about 3 or 4 tech's worth of time, and then you factor in you have to build the thing first in some cases.
And on top of this, it screws you over by deleting all your 'free' temples as soon as it expires, usually causing widespread rioting unless you're efficient enough to remember and somehow perfectly prepare for it expiring (or just potentially waste a turn's tech by lazily pumping the Lux slider for a turn).
And then, if you want Temples, you have to build them all again anyway, at a point in the game when you're way to busy building everything else.
It's not as if Temples are even that over-powered to begin with to warrant them not being a permanent freeby. I can only imagine its because it doesn't 'balance' well with the new Cultural Victory scenario. The Great Wall, however, doesn't even have that excuse... for the Great Wall, they, uniquely, decided to go with... realism! Lol