Is it always a bad idea to shoot during noontime?

[Overread]

yes and no - again this golden hour rule is much like the rule of thirds and many other photography rules - its a guidline to follow, but it should not limit not define your work. Shooting at any point in the day on any day will have limitations - that is nearly always the case with work done outside of a fully controled studio (even then there are limits). Bright midday sun might be harsh - bit it will give you some great light for fast shutter speeds for flying birds - sure you can do this in evenings too - but the bird might not be there in the evening either.
Macro work benefits quite a bit - sure you still have to watch the highlights a lot - but a reflector set to diffuse held over the sun will give you a softer light and still give you enough ambient light to work with.