I guess after Bitcoin reached its first ATH in 2017, some mainstream Media started referring to ALTs like XRP and ETH by the abbreviation of crypto. I started hearing crypto from that time, though I may be wrong this is my opinion.
Right, I agree with you. Back in the year, 2017 when bitcoin reached $20k, that's when the time the word crypto abbreviation became popular. And I guess people tend to create a shortened form of the word because it's much easier to read and write.
There is a common use of abbreviations in almost all languages. The word crypto is one of those options, but it should be noted that the meaning has evolved over time and with the expansion of its use. Prior to the launch of the first cryptocurrency, the word crypto was essentially a symbol for cryptography. Later, after the emergence of Bitcoin, i.e. the use of cryptography to create a payment system as we know it today, the word Crypto became primarily a symbol for cryptocurrencies, i.e. currencies based on the principle of cryptography.