I'm gonna say it's the fact that Lucia's not even in college yet while Gustafsson has already proven himself in a men's league.
Both have room for improvement, but Lucia's chance of busting is much higher. Typical risk/reward.
While Lucia's bust risk is high, it's still nowhere near as high as a goalie who has little to no experience on North American ice and is at best third on the prospect depth chart. There's still significant, legitimate concern about how Hackett will turn out and he has a far better resume than our Swedish friend.