That is modern protocol, just not as common as the 'loop-in' method.
It's not wrong, just different.

It is wrong. It probably should be banned under some sort of Disability
Discrimination Act. It will totally bugger up any hearing aid inductive
loops when the lights are turned on. When routing cables, you should always
ensure that the current flows are balanced as much as possible. This can be
difficult for central heating systems if the wiring's all over the place,
but easy enough to do with lighting, provided you take care with any 3 way
lighting to only feed at one end and don't loop neutrals separately from
lives.

Christian.