I would argue the reason you feel the need for so many anti-blue cards is the lack of Cavern, lack of ability to play Thorn or Thalia on turn one (because you're missing moxen and crypt), and the tempo blowouts of having DRS misstepped or the DT target Forced.
White Eldrazi just solves all these problems so much more efficiently. Instead of relying on a third color and a turning on 4 otherwise dead blue cards to hate out JVP, it just plays Karakas. The value over replacement of Karakas compared to Scrubland is tremendous.
Instead of packing so much redundant blue hate (Wingmare, Thorn, Thalia, Thalia, and Spirit) it plays some more broadly powerful cards instead (Displacer, Smasher, TKS) and uses Cavern to make sure the important hatebears it does have resolve.
You are spending a lot of spell slots to solve problems White Eldrazi addresses with its mana base.