Back in 1995, the price of a carded NCLT dollar coin was not all that high - just 2 or 3 dollars, if I recall correctly? I know several people in my coin club who bought some at the coin show, then went into town after the show and deliberately spent them, just to try to get "unusual coins" into circulation and maybe spark some new coin collectors into existence.
However, it should probably be said that the majority of NCLT coins found in change, would have been put into circulation by thieves - people who knew little and cared less about collector value of the coins in their possession, and just saw the coins as money. Sadly, all too often those "thieves" are family members of coin collectors. If you've gotten hold of a bunch of $1 coins and you want to turn them into cash with as little scrutiny as possible, you're not going to take them down to the coin dealer and maybe get $2 for them, when you can get $1 for them just by spending them, banking them or feeding them into a vending machine.
Finally, these cards aren't all that great at preserving and protecting a coin. A carded coin, sitting around in an adverse environment, can get damaged. A coin might also get damaged in flood or fire. Nobody wants to pay a premium above face for a damaged coin and/or a damaged card; dealers who end up with such coins, will likely write them off and bank them.
And yes, the "surplus coins" theory is bunkum. The made-for-circulation production streams and the made-for-collectors production streams are completely separate from each other. They are made in different parts of the mint, by different people, and probably on different days. There simply isn't capacity within the Mint, even back in 1995, for them to say "collectors don't want these coins, so let's just toss them in the hopper with the rest of the dollar coins". The accountants would throw a hissy fit if someone tried. There are no "surplus coins" in the Mint gift shop, and never have been; the NCLT coins, once made and released for sale, stay on the shelves until they're sold, even if it takes them years to get rid of them. For the RAM, historically, it hasn't needed "years" to clear the stock.
If for some reason they managed to produce "surplus coins" that they didn't have cards for, they'd simply print more cards. It's not like they were limited-mintage or anything.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis