I'd be interested to see the evidence for "terrible for you".

Hypnotics just make you sleep - they don't treat the cause of the insomnia. (For some people they're great at kicking you back into a routine.) There's evidence that long term use can create rebound insomnia.

Here's a guide for general public stating the need for using the meds short term:-

(http://www.nice.org.uk/nicemedia/pdf/TA077publicinfoenglish....)

Here's a slightly more technical document with links to the evidence that they used:

(http://www.nice.org.uk/nicemedia/pdf/TA077fullguidance.pdf)

Here's a guide aimed at clinicians with many links to good evidence:

(http://www.cks.nhs.uk/insomnia/evidence)