While it can only serve as a mana dork for a single turn initially, there are so many cards that produce Food tokens that it can reliably supply you with ramp and fixing for much of the game
I believe that if Tedin didnt have this card picked up by MTG, it would be hanging on a wall as part of an exhibit in some museum
Mechanical usefulness, plain collectors value, and sometimes rogue elements, can influence these sudden shifts
A one-mana play that really shines when mutated upon would be an upgrade, but more than anything Sea-Dasher Octopus needs a two-mana counterspell that really punishes opponents throughout the game
Simply put, this cards power and versatility cannot be underestimated and its secondary effect is the icing on the cake
Theres no cost to pay or drawback to the player, it just does so because it was printed during an era when you couldnt lose the entire duel off a single misplay