On: How to read Korean in 15 minutes

[mansr]

Another exception is 시 being pronounced [shi].

[guard-of-terra → mansr]

That's no more exception than st in german being pronounced [scht].

"It doesn't produce minimal pairs".

[mansr → guard-of-terra]

Whenever pronunciation of a letter depends on the surrounding context, you have an exception.

[guard-of-terra → mansr]

There is no way for a pronunciation to not depend on the surrounding context. You do not spell words letter by letter.

Thus minimal pairs are the king.