Because the Finn who created it didn't want to seem like a showoff so he let the Swedes take the credit.  

 The term "Swedish torch" likely arose due to historical associations and regional proximity rather than direct attribution to its origins. Although the torch or log stove concept is believed to have Finnish origins, it spread across Scandinavia and Northern Europe, including Sweden, where it gained considerable popularity and was widely adopted. Swedish soldiers in the Thirty Years' War are often credited with popularizing this technique across Europe, as they reportedly used it for warmth and cooking during campaigns. The widespread use of the torch by Swedish soldiers may have led to the association of the name "Swedish torch." 

 Okay interesting, I need to try out this. thanks for the answer.