Why is Electrical Voltage Tester Better?

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I was reading this Fluke multimeter safety manual and I came across this sentence: http://faculty.riohondo.edu/jfrala/fluke_multimeters_-_abcs_of_multimeter_safety_multimeter_safety_and_you_application_note.pdf

"Non-contact voltage detectors are a quick, inexpensive way to check for the presence of live voltage on ac circuits, switches and outlets before working on them."

Question 1: Why exactly is this relevant? If you are going to work on a circuit, why not use your multimeter directly to check the presence of voltage?

I thought about safety but I can't see a real reason. If you are worried about safety, once you measure the presence of voltage with the non-contact voltage detector you would need to use your multimeter next anyway (and the "safety" you supposedly got from measuring it with the the non-contact detector would becomes useless).

What am I missing?

Question 2: Why exactly are these called "non-contact" voltage detectors? You still need to physically insert them into an outlet (or somewhere else you want to check) in order for it to work.

The flow of electrical current is measured by placing an electrical tester at two points in the circuit. A voltage tester is the simplest of these tools. It consists of a small neon bulb with two insulated wires attached to the bottom of the bulb housing; each wire ends in a metal test probe. This type of tester is always used with the current turned on to determine whether there is current flowing through a wire and to test for proper grounding. It is also used to determine whether adequate voltage is present in a wire. Look for a tester rated for up to 500 volts.

To use a voltage tester, touch one probe to one wire or connection and the other probe to the opposite wire or connection. If the component is receiving electricity, the light in the housing will glow. If the light doesn't glow, the trouble is at this point. For example, if you suspect an electrical outlet is faulty, insert one probe of the tester into one slot in the outlet and the other probe into the other slot. The light in the tester should light. If it doesn't, the outlet may be bad.

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To further test the outlet, pull it out of the wall. Place one probe of the tester on one terminal screw connection and the other probe on the other terminal screw. If the tester bulb lights, you know the outlet is malfunctioning -- there is current flowing to the outlet, but it isn't flowing through the outlet to provide power to the appliance plugged into it. If the test bulb doesn't light, there is no current coming into the outlet. The problem may be a blown fuse or tripped circuit breaker, or the wire may be disconnected or broken behind the outlet.

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