The specific quote and sect you're referring two has two cultural problems and when those are resolved the situation makes sense.

The sect has a huge cultural bond with what translates into English as abstract one liners of the shock therapy genre, combined with gaining insight by teaching students how to expand that... discussion starter into an entire discussion. So that's the first problem resolved. No holy clay tablets with these dudes, shocking "Trumpian" one liners that belong on TV clickbait news are how they roll.

From the point of view of the sect, your enlightenment is your goal and its obtainable via internal effort and right thinking so if you think meeting the right dude makes the religion all about you and who you meet ... or if you think you'll get enlightenment solely by meeting impressive people ... or if you think impressive people are by definition of impressive those who are more enlightened than you are ... or if you think your religious path should be about other people not yourself and your own path to enlightenment ... or if you think people who brag about enlightenment to you are anything but the lowest form of scammer and criminal, then you're wrong at the level of basic core beliefs of the sect. You might personally disagree, whatevs, thats just how they see it.

BTW the kill bit is very intentional. Per the sect, similar to most human organizational codes, killing other people is pretty much about the worst possible way to proceed on your path to enlightenment and this is their peculiar way to declare that one itty bitty little step underneath the sin of killing people is the slightly less sinful mistake of worshiping other people as idols. You're better off having lots of sex and eating meat and squashing (literal) bugs than becoming a cult member, at least WRT getting anywhere on your religious path. Or maybe you could read it as at least WRT the path to enlightenment, becoming a cult member is perhaps roughly as effective as becoming a murderer (aka extremely strongly advised against)

So yeah, bringing it back around, in that sect, kinda the whole point is making your religious practice that of venerating some dude who brags a lot about being more enlightened than thou as you mentioned as an example, is totally not seen as useful. That doesn't necessarily mean you have to kill him but it means venerating him would be as useless as becoming a murderer in other words maximally ineffectual.

Note that there is a larger variety in belief in Buddhism than Christianity. In Buddhism there are many who would honestly disagree with this particular sect's advice about how much you should trust wandering opinionated gurus. Usually they have a great pile of differences in religious and non-religious culture such that they're more immune, have semi-elaborate defense mechanisms against false prophet cult leader type situations. So this sect relies on "You're an idiot if you join a cult" social pressure whereas other sects rely on extremely low levels of freedom for the theoretical cult leader due to traditions and maybe trust in ancient era hierarchical authoritarianism such that lunatics won't be appointed as central policy and if central policy sucks, at least its far away, and on average that works pretty well.