Welcome to garden.org, Frank. What a shame they have hacked up those beautiful plants! They may recover in time, but what an ugly mess.
No this is most definitely not a way to prune clivias or agapanthus. They grow a graceful fountain of leaves, and the leaves are needed to keep the rhizomes healthy and help the plant make food for itself so it will bloom.
You may want to tell your homeowner's board that those clivia plants sell for around $50 apiece so they are sacrificing some very valuable, established plants to inexperienced gardeners with an idea of making things look "tidy".