I see the point on the card being difficult, and I am also aware of why cards giving VP chips or possibly any VP that do not harm your deck, need to be carefully. But I also imagine people thinking a non-terminal or cantrip Curser is too powerful before seeing Familiar, or that costs other than coins are absurd (hey, some people still say this). I myself thought about cards picking things from the trash, but ended up thinking there was probably a good reason for that not to exist. Same with costs $1 and $7. Same with VP chips (I like those, but I like the careful balance between VP and useful cards you need to do in games without them, because its an interesting and novel thing about Dominion).
Anyway, I'm not defending any particular implementation, and I can agree about all comments made here against them. I just still don't see that there is enough evidence for the strict impossibility, and providing examples clearly does not work because its way easier to take down an example that does not work than to come up, in a couple of minutes, with one that does work.