Why do genuine football jerseys have poor quality iron-on sponsor's names?

[True Believer]

Genuine football jerseys from the established brands like Adidas, Nike, Puma, Umbro etc. don't fade or require ironing. They can typically be worn for up to 20 years without losing their shape or colour. Why then do kit manufacturers use low quality heat pressed decals for the sponsor's name? They usually peel off or disintegrate after about 3 years of washing, thereby ruining the appearance of the jerseys.