I prefer it to say having an entire folder of emails I haven't received replies on as it allows me to specifically manage messages that are important enough to require a non-replied reminder.
I guess if you're so busy you lose track of these things? But again...
In the end, not everyone's usage pattern is the same, and people end up using email for things other than direct communication (such as tracking future work items). While not ideal, for some it's easier than dealing with a completely separate application that integrates to various degrees.
I feel this pain.
Shameless plug: I wrote an open-source version of Boomerang/Followup.cc that is designed to be self-hosted, specifically because of this concern: https://github.com/ChimeraCoder/go-yo
(For the record: I like script in the original submission script, but for me, I rarely use the Gmail web interface, so I had to make something that works over IMAP).
It's still a WIP, but I've been using it myself for the "bounce-back" feature for the last several months.
There is that privacy/security issue though. I always look at web based email as being inherently insecure anyway.
Matt Galligan and I put together a version of the No Response Apps Script back in June also. It's more basic than this, but might be easier as a starting point for modification. https://script.google.com/d/11c63LM4rOTxCP5uqffLDhIaEQFmNo0p...
I've been loving Apps Script for things that are too lightweight to need something like Boomerang, with a server and a full browser extension, but heavy enough that you can't do it with a search string.
