Up front I have to disagree. Although I can both knit and crochet, I could crochet for a LONG time before I could knit so I have an affection and passion for this craft, and can see the advantages that it has over knitting for certain projects.
Here is my list of the advantages of crochet:
1. Crochet is faster than knitting
2. Crochet is more forgiving of your mistakes than knitting
3. There is only one stitch on your hook, leaving less room for 'dropped-stitch disasters'
4. Crochet lets you create wonderful three-dimensional stitches, that give your project depth
5. You can put a crochet project down at any time, and don't have to 'finish a row'
Yes, it is true that crochet often uses more yarn than knitting. This is due to the 3-D nature of the stitches, and with this comes the negative. That the heavier stitches create a firmer garment, less inclined to drape. This can be overcome with wise project, yarn and hook choices.
So here are my five tips for getting your crochet garment to drape:
1. Chose a project that has a more lace or lattice effect.
2. Chose the weight of your yarn wisely. I would suggest no more than sport weight (5-ply) with a strong preference for lace (2-ply) or light fingering (3-ply) yarns.
3. The fibre you choose also makes a difference. I like baby alpaca, silk, silk/mohair & wool/silk blends.
4. Needle size. You may want to play around with a larger hook size to see if it makes a difference to the drape of the garment.
5. Blocking. Everyone blocks anyway right?
Still need convincing? Well here are some projects that I found on Ravelry that I rest my case on.