The current debacle is really showing up the inherent weakness in the Holyrood voting system.
Actively works to prevent a single Party forming a majority which can then afford internal dissent to hold it to account. Fragments the Opposition into competing factions who end up focused on each other rather than Govt. Gives disproportionate power and exposure to minor players without accountability.
Before the Greens this is the mechanism which allowed the SNP to coattail as the bit player getting all of the credit and none of the flak.
Contrast with FPTP in WM where the LibDems went into coalition only to end up getting all of the flak and none of the credit.