I am speculating that sticky tent flies come from being stored in hot conditions, say a garage or an attic.
I asked Eureka about that. They said some of the earlier materials just tended to degrade over time. They had a limited lifespan under even the best of conditions. They assured me that the newer materials are MUCH better. Hope so.
My tents were (are) always stored in air conditioned places - either a bedroom or a dry (air conditioned & dehumidifier) cool basement. It didn't even see the light of day as much as I'd have liked it to (I was in graduate school for far too long).
When I was a teenager I sewed a Frostline kit tent (the 2-person Kodiak if anyone remembers Frostline kits), and the coating on that tent got sticky too. That was even sadder for me since I sewed it myself.