Sorry, you should have taken the hint. That answer makes no sense at all.
Even if BD were to disappear, their PS3 would continue to play every BD movie they ever bought until their PS3 goes to the great game console graveyard in the sky.
If current PS3 owner's are concerned about the future after that would happen, then they also wouldn't buy any PS3 games either, because the situation is identical, especially considering SONY has dropped PS2 compatibility at this point, so when (if) the "PS4" comes out, it's not likely to be compatible with their existing PS3 game library.
It simply makes no sense that PS3 owners wouldn't buy Blu-Ray discs because they are concerned about the future of Blu-Ray. Based on that logic, they would never buy a PS3 in the first place, because it's in a "format war" with the XBOX 360 and the Wii. And if they did get a PS3, they would never buy any PS3 games, because they would be concerned about the future of PS3 games is the PS3 fails or gets replaced by something that won't play PS3 games.
Is it that hard for you to admit that the reason so few PS3 owners are buying Blu-Ray discs is because they simply aren't interested in buying Hi-Def movies?