Yes, we (the players) choose where to dig, but we can only dig what's on the map, and if only (just quoting the OP here) 'worthless (poor and common) artifacts' are what's buried, it's not really us (the players) that are in control. You can't fault a person for choosing a low valued prize when the only options are low valued prizes. It's a "get a low valued prize, or get nothing" situation.
So how about we hold the person accountable that's putting poor artifacts into the ground? (;
Or the person that's defining the category %'s ...
Less of: 72% poor, 16% common, 8% uncommon, 4% rare, 0% epic, 0% legendary
(This is what I'm seeing on Netherlands right now, was hoping to see better artifacts as the maps got bigger but doesn't appear to be the case, still mostly Poor and Common).
And more of: 1% poor, 2% common, 33% uncommon, 53% rare, 10% epic, 1% legendary
Or even: 0% poor, 3% common, 33% uncommon, 53% rare, 10% epic, 1% legendary
On the later maps, there's no point in getting poor artifacts at all, as they contribute so little, and players will already have some decent Common and maybe a few Uncommon artifacts by this point, and it takes sooooo many poor artifacts to trade up to an Uncommon (25? 4 poor artifacts for trade ins + 1 poor artifact to upgrade = need 5 poor artifacts tog et 1 common artifact, and takes 5 Commons to get 1 Uncommon => 5*5=25 poor artifacts)