This is one of those things that, hopefully, cuts down on people using the courts for petty vendettas by filing frivolous actions against people. It is painfully easy to get a temporary injunction and not all that difficult to make it permanent.
The threat of a sizable bond can help deter people from filing nonsense junctions out of spite or for other reasons. Frivolous actions simply waste a court's time and run up considerable legal fees for defendants. Those resources should only come into play in serious actions.