Why does the Holy Spirit get this special distinction, even over Jesus?

I know I have written about this verse before but it is one that puzzles me just a little.  Not a big deal type of puzzles me but more of just a curiosity. 

Mark 3:28-30(NKJV)

“Assuredly, I say to you, all sins will be forgiven the sons of men, and whatever blasphemies they may utter; 

but he who blasphemes against the Holy Spirit never has forgiveness, but is subject to eternal condemnation”—

because they said, “He has an unclean spirit.”

So you can bad mouth God and if you ask for forgiveness, it will be forgiven.  You can bad mouth Jesus and if you ask for forgiveness, it will be forgiven.  But you bad mouth the Holy Spirit and you are toast.  No do over.  No second chance.  Toast!!!!

I'm just curious why the Holy Spirit gets that distinction even over Jesus.   Of the Trinity is the Holy Spirit like the little brother?  Baby of the family so to speak?  Parents are many times accused, at least by older siblings, of babying the youngest.  And of course, big brothers (Jesus?) always give protection to their younger siblings.  :)

Or is there a more spiritual reason?  I really don't know.  I just find it curious.  Just another one of those things I will keep an eye out for in further studies.  Part of why I love studying Scripture!