Why are regenerative logic circuits called regenerative?
The key aspect of circuits like latches is that they are digital, rather than analog. In order to achieve this, an noisy input signal with a voltage that can range from ground to \$V_{CC}\$ must be mapped to ground or \$V_{CC}\$. If the input is 0.75 \$V_{CC}\$, the output cannot be 0.75 \$V_{CC}\$, because that's an analog output, rather than digital. To achieve this conversion, latches use positive feedback to amplify the signal. In this way, inputs greater than some threshold will grow until they reach \$V_{CC}\$, and the opposite is true to. This falls under the principles of regenerative circuits https://en.wikipedia.org/wiki/Regenerative_circuit, but you can also think about how if a signal diminishes slightly due to losses, when you feed it into one of these logic circuit the signal "regenerates" its digital properties.