What quote? And yes, in my opinion some IRC clients have suboptimal defaults or missing support for this. It's a shame, but changing your nick to emulate a built in IRC command is in no way a solution. Away is standard, and every client should support it. In the end it's a question of the channels rules, but spamming nick-changes is annoying-- especially because people use different formats and simple filtering won't catch all cases. In addition it also breaks queries and might change your identity from a trusted nick to one that could be... everyone.
You're advocating using a hacky workaround that stems from client-side UI issues, instead of using a well-defined built in message. This just seems wrong to me, in every way.