Here's a few off the top of my head: a) you have to cut them to move a cable b) you have to have cutters to cut them c) they're usually cinched WAY too tight

Here's a few off the top of my head: a) you have to cut them to move a cable b) you have to have cutters to cut them c) they're usually cinched WAY too tight around a cable bundle, potentially damaging the cables inside (esp. an issue with fiber) d) you can't reuse them once you've cut them e) those edges that get cut to 'clean up' the appearance become VERY sharp (I've bled multiple times, sticking a hand into a cable bundle) f) because you can't reuse them, there's a chance that once you take it off, you won't be able to refasten the cables (i.e. you didnt make sure you had enough extra ties to do the job) g) you can't 'loosen' them to fit a new cable through, while still keeping everything else bundled - you have to completely destroy them h) lack of re-use and lack of 'loosening' means that n% of the time, techs will be lazy and just not re-do the cable ties at all.