I disagree with OP for many reasons.
First, basically the whole tour is "slow HC season." So it seems like you're basically calling out Miami and IW. Well, Miami is disappearing, but IW is the 5th most popular/successful tournament on tour, so good luck "scrapping" it. Also, that explains the "build up." It doesn't build up to nothing, it builds up to the two largest tournaments outside the majors.
Second, while I'd love a longer grass season, sure, moving clay season up by 2 months will completely change the entire tennis calendar. Just not doable.
Finally, I see the first part of the season like this: Australian HC season is short and kicks off the season the right way, with what everyone wants, a slam!
Then the season really begins with 2-4 tourneys per week: the Latin swing, the French tourneys, and the American HC tourneys. A few 500s.
They eventually converge at IW/Miami for some big points/$$$, and then clay season begins.
Seems sensible to me.
I'm all for speeding up courts, more grass tourneys, and schedule changes in general.
But moving IW to early January, or eliminating it altogether? No thanks.