This thread is rapidly turning into a conflation of two different discussions.
But I rarely do "gimmes" with treasure. That's something earned, and discernment is part of the process. It has been since 1E. If nobody had appraisal, they'd better carry all the gems. If you don't have Identify, have a Dwarf to handle the stuff first or cash for the temple, etc.
Well, okay, if you say so, but the game as written today, 4th edition, not first, doesn't require that. It doesn't (at least by default) lump curses on you if you touch a magic weapon without checking it first. It doesn't suggest planting traps in every other hallway just to punish the party for being so foolish as to walk along without poking the floor with a stick. It doesn't suggest handing over lots of heavy but worthless treasure just to show the party how badly they screwed up for having nobody that can appraise effectively.
So yeah, if your party gets back to town and you shout "HA! Those thousand jewels you traded for are shiny glass beads worth two copper each!", you screwed the party.
But that's your choice. If you don't like "gimme" treasures, that's fine. My philosophy is to give out the treasure pretty freely; they've already earned it by getting past the combat, the puzzle, the trap, whatever the challenge was. I might choose to make discernment part of a particular puzzle or RP encounter, but it's by no means the default, and lacking it means the party will have a harder time
beating the encounters that depend on it, just like a party with low attack bonuses will have a hard time beating a combat encounter or a party with bad climbing skills will have a harder time getting past the skill challenge of a treacherous cliff. In either case I'm not going to reduce the reward for a successful encounter due to some confounding factor of a missing skill bonus.
To me, what you're talking about is equivalent to saying, "Okay, you slew the giant spider. In the webs above your heads, you can see a number of shiny objects. Roll jump checks to see if you can reach them and pull down the treasure. Oh, by the way, the webs are fireproof and you can only jump one time." To me, that's a screw because you're refusing to let the party find any other solution than the one you specifically intend, and if they roll badly or just don't make it... too bad, so sad, shoulda put more points in Athletics. It's not "challenging their weakness", it's punishing them for having other skills, and refusing to let the players use creativity to make up for weaknesses.
In any case, that's all off topic.
As Keterys pointed out to you a page back, all I've been saying here is that the book doesn't require such barriers before the party can play with their new toys, so it's up to the DM as to whether the party will miss magic items due to having low Arcana checks.
In your games they will; in my games they won't. You can bicker and quibble about whether or not that constitutes a 'screw', but that's just personal opinion. Obviously no DM
thinks he's being unfair to the players.