Mostly for the advantages of purity and the trend of Haskell code I writing just being correct the first time. Also, with the help of dom-selector[0] it is very concise.
I'm also using wreq[1] recently which has a great intro tutorial and is very concise with the help of lenses[2]. Mind you, I only use the most basic lenses but that has been enough for me so far.
I look forward to trying taggy-lens[3] in the future which is a more lens based approach of parsing html. Though it's hard to imagine anything being more concise than the dom-selector approach.
To go back to your question again though, Haskell has enabled me to write mostly bug-free code quickly and there was more than enough library support for screen scraping. The biggest problem was trying to pick the tools/libraries to use for my task.
