Part of it to be fair comes to telnet being ubiquitous. I've used any number of aix / hp-ux / solaris / Linux / windows / whatever systems over the decades, with limited or high privileges, and telnet was the one command that worked on all and could within 3 seconds and no fancy docs or knowledge and additional tools tell me the basics of what I needed to know. Are there better tools? Ab so freaking lutely. But telnet is there :-)

My 100 Croatian lipa