I think the key element here is that the other kid tried to prevent my son from running the trade by me. I think he was 10 or 11 and my son was only 6 at the time. It's very easy for a ten year old to railroad a 6 year old. Having the rule in place makes it easier for someone to stand up to a person that's aggressively trying to push a trade through.
Pressuring is wrong.(I and others hit this before) .... But the other answer is that 6 year old shouldn't be allowed to trade the Uxie LA in the first place. If it would make you mad
that your 6 year old makes a bad trade, don't let them trade, or only trade with a trade binder that you have your tradeable cards designate. If you have to approve the trade, doesn't that really mean you(we the parent) have to make the trade ultimately.
I say this because.....I personally have a rule that since Dad(me) finances our hobby, and I am a competitive player, and I do CARE, thus all trades are basically done with me. (If at all.) Since I have enough money for this hobby to buy a few boxes and e-bay cards for our family card collection, I don't bother much with trading because I don't want to trade for cards that I can more easily just get off of e-bay, and then I don't have any sort of guilt of getting someone's Claydol's that I knew where valuable. I am very good at identifying core cards and e-bay them at a good price before the market get's good at pricing them.
I am reminded often that this is a child's card game. Trading cards and the negotatition of those trades is a growing experience. For kid's with more limited resources, trading is the only way they are going to get cards and get a competitive decks. Good for them. Some kid's that can't figure out(or don't really care) which cards are needed for a competitive tournament deck so be it.
There is a league near our house where it is mostly dominated by NON-TOURNAMENT playing younger kids.( I haven't been there) By all accounts, the kid that go do enjoy that league, but many of their parent's don't take the next step and go to tournaments. Some of the older kids that I do know do go there and get many good cards from trades and such. Those older kids are competitive players and have limited resources for cards, and do have to rely on making trades to get there decks made.
The question is if they go and trade for spiritombs, for non competitive rare cards..., those spiritomb's might NEVER ever see there way into a non-competitive 8 yo players deck, is the world a worst place for it?
A violin is just pieces of wood and string, but needs a violinist to bring out the music. It is same thing with good cards. If the players who have certain cards can't understand the value (not money, but worth in a deck), and someone else does appreciate there use in a deck and trades something that the other player want's to aquire it. That person now with that resource now win's tournament because of that trade, isn't the world a better place.
This is competition and capitalism versus socialism sort of analogy. The value creators create value by having a vision and acting upon it. They create value in this world that other didn't see or care to see. As long as transactions are done without undo pressure, it is good for those get those done, unless you happen to be one of the players that player beat because of him having that spiritomb. If you disagree with this, then you basically have to go to the extreme and say, everyone play with a starter deck, because by allowing someone to have better cards/deck than another is wrong.