Thank you very much for the insight guliaditya.
I won't deny what you've said, which I totally agree. But remember Sri Ram is known as Maryada Purushottam. He took birth to show how a man should act. Like a man, though being the Supreme, he showed respect to Shiva.
If he wouldn't have done that, common man would have not shown respect to the Dearest of Devotee.
If a pure devotee has written Smriti, it can never contradict Shruti.
And Goswami Tulsidas needs no introduction in that respect.