This type of crimped terminal is widely used in industry. They were designed to take place of tinning stranded wire.
By crimping them in a sleeve it minimized the chance of stray strands breaking off and the need to solder.
So they saved time as well.
Solder makes wire brittle. That's why it's a nono in aircraft.
These crimps require a special crimper as well. You might be able to use them with a standard STA-KON style crimper, but they are designed for a 4 way crimp.
The tool is expensive, but not overly so. I have a bag of probably close to a thousand of those here at work.
--Shane
WP2ASS / ex KD6VXI