Unusual. The ones we watched fledge and then leave the nest in France were anything but that, and those we had in our garden in the UK were likewise gentle (though males would chase off other collared doves, and I believe will chase off predators too; they’re not known for being aggressive to other species).
Collared doves are known for nesting close to human habitation. Their favourite sort of home is near a farm, where they can feed off grain spills. Where the food is plentiful then they will naturally multiply.
@toryroo , the one you saw was probably a male. Males present females with sticks for the nest. But if you’ve decided you’re going to scare them off, do it without feeling guilty: they’ll find somewhere else, and you’ll probably still hear the cooing in the evenings!