Earlier editions where perfectly clear: "You cannot cast this spell on a natural weapon, such as an unarmed strike."
If I am not mistaken you are quoting the 3e version of the spell. 3e also had Magic Fang which worked on natural weapons.
1e’s Enchanted Weapon spell did indeed only work on weapons, it was also
Reversible and a 4th level spell. Frankly, in 1e I saw it used as Disenchant Weapon more than as Enchanted Weapon, as
magic weapons in general were more common and
required. 1e monks could also technically by RAW
stun and
kill creatures they hit, but did no damage to, e.g. hitting a demon with an unarmed strike and rolling well.
2e I believe was similar, except of course no Monks as a PC class, and Druids were an example of Specialty Priests.
Also I think if fair to state, 1e and 2e
were not balanced systems.
As I have stated, the rules being discussed, are in 5e almost identical to the 3e rules, except for the removal of Magic Fang as a separate spell, and a change to the verbiage of 2nd level Magic Weapon,
away from the clear verbiage that Paul F quoted to the more broad “non magical weapon” language currently employed today.
The clear impact engendered by this change is the 5e Magic Weapon spell, wether by intent or accident, can in one handy dandy package handle the duties of both 3e spells Magic Fang and Magic Weapon.
As for the claims by Sanc and Paul F regarding people “telling them how to play”, myself and others have only detailed how we hold the testimony of Crawford’s Tweets as having less evidentiary value than yourselves. I
wish this was less threatening for you.
That said, I have still not seen a convincing argument for why Magic Weapon would be unbalancing if applied to natural weapons in 5e.
History Synopsis:
1e: Wildly different rules ecosystem to 5e( like comparing the Tropical Antarctica of the past to the Antarctica of today), Enchant Weapon 4th level spell
2e: as 1e only No Monk class, Druids are one of many Specialty Priest classes...rarely used imho.
3e...see post above
4e...wildly different rule ecosystem, power verbiage is specific to class/power in most cases.