OP, the only part of the dev answer you quoted that I don't agree with is the part where they say they wish the cost of ANY unsocketing was much higher, closer to what unsocketing the Marquise is. THAT I don't think would be a good idea. The way I see it, part of the point of having an artisan be able to unsocket stuff for a small bit of gold, and leave both the item AND the gems intact, is a step up from Diablo 2's unsocketing which required a Hel rune, AND whatever you put into the item gets destroyed. So right there, D3 evolves it a bit. Maybe the price for unsocketing smaller gems makes it easy to recycle and reuse the gems you have already, that's a good thing.
The fact that Marquise costs so much, though, is that if you want to socket the TOP TOP TOP tier of gem, then you need to make a smart choice with it. Someone else posted about this and said "well, what if I pay a ton for a Nat's chest and throw a Marquise Emerald in it, then find or buy a better Nat's chest." The key there is to fully do your research, and decide "is this particular Nat's chest good enough that I can socket this gem into here and not likely find a better one?" The high cost shouldn't be seen as a "punishment" or "Blizzard just wantz yo monehz!" It's just trying to get people to use their heads and not throw Marquise gems into gear without thinking. Unsocketing other gems doesn't cost nearly as much, so if you're looking to do some gem switching, go with a tier lower.
Marquise tier, though, is MEANT to be the highest possible, and should be socketed into gear and weapons that are the highest tiers as well.