You are right - a tabindex is not needed by the splitbars, which cannot be dragged and do not contain expand/collapse buttons.
We have modified the Splitter code and changes will take effect in the next Kendo UI builds.
In the meantime, if you want to remove the tabindexes manually, then use a different selector, which will NOT target splitbars that need a tabindex:
If you don't need to support keyboard navigation, the tabindex doesn't matter.
I have updated your Telerik points.
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