While I like your Bash script, I don't think I will ever use brainwallet addresses. I'm quite well aware of the unreliability of my own memory, unless I train and use memorized details on a regular basis, emphasis on regular. I'm simply too old to keep stuff solely in my head. For me this would be a sure recipe for desaster, especially when I don't have to use it frequently.

If I were tempted to use brainwallet addresses, I'd use also additional protection with BIP38 encryption, but I'd keep'n'hide a written backup for sure, which kind of defeats the purpose of a true brainwallet. I shall not be tempted...