What is poorly handled and what should've been different? The security issue seems to be the obfuscation that is offered by all URL shortners and redirects, and most email links usually have several layers of them.
Which raises the question of the purpose of link shorteners anyway.
They are usually so obscure and jumbled that reading them out loud to someone would be slow and awkward ( "that's goo dot gl, no e" ). So what is the use-case?
They're still shorter, and less likely to line-wrap and break older clients. They also help to obfuscate certain tracking info and/or protect them from tampering.
Also you can set a custom shortname in almost all of them, if it's available.
They are usually so obscure and jumbled that reading them out loud to someone would be slow and awkward ( "that's goo dot gl, no e" ). So what is the use-case?