Yeah, it's easily abused and trivial errors of judgement create non-trivial problems later down the line.

IMO part of the problem is that nested LESS/SASS looks just enough like JSON to mislead inexperienced devs, who often try to treat the nested structure as an object, rather than thinking of it as a string-builder.

It invariably ends up creating huge swarths of pointless specificity and stylesheet bloat.

CSS offers plenty of ways to hang yourself without resorting to SASS. The people who are dangerous with SASS tend to already be just as dangerous with plain CSS, in my experience.

The additional options for self harm are well offset by the features.