If this is the bike in question;
...I think I see where you're going with the "suicide clutch" as with just a coaster brake, you've nothing else on the bars & it'd be nice to clean 'em up completely...
In my opinion it isn't relocating the clutch lever that's an issue - in operation these two stroke kit motors only need the clutch to come to a complete stop without stalling, so in a "panic" stop you really needn't take a hand off the bars in any case. Even though stop n'go stuff would be kind of a pain it really isn't a danger, it hasn't the oomph to launch into traffic & you needn't shift in a turn as you can't shift anyway... with a locking lever (stoplights etc) I don't see why it'd be partic a problem.
I think those opposing reactions are more relevant to the true tank shifter/rocker foot clutch multispeed setups, which were a bit sketchy TBH - but if we're worried about safety, it'd be the lack of a front brake on that bike the bigger concern & adding one would entail another lever, defeating the point of the "suicide clutch".
I don't think relocating a locking clutch on that bike would make it any more hazardous then riding w/just a coaster & that's usually what folks warn about... personally I'd add brakes instead as I ride too hard even for the ones I've got sometimes, but if you're going for the clean bar show bike weekend cruiser & know the brakes are not so hot I can see where that might be attractive.
Bear in mind folks warning is usually in good intent & if there's any lack of info, folks will tend to have to assume inexperience - and we do tend to get those without much/any bicycling experience, those that may underestimate a motorized bicycle & become a statistic fairly quickly. So folks err on the side of caution & there's enough new riders it becomes almost a mantra, hoping to spare some of the road rash we've all gotten or are bound to get.
An example - I often ride my ebike no hands with the cruise control set to floored, not a difficult "trick" by any means but kinda stupid & definitely dangerous. Not only would I not advise no-handed riding at even ebike speeds, I've long cautioned regarding the hazards of cruise control on motorcycles & cars, let alone motorized bicycles & if anyone asked how to install one, I'd prolly mention they can be dangerous too...
...but that doesn't mean I don't use one myself & even think it's kinda neat, I just can't help someone be as dumb as me & feel good about it lol, perhaps that helps with some of the replies you've gotten