Rated 5 out of 5 stars
> For the record, as of 11/02/2010, Firefox 3.6 has 50 million downloads. This add-on has 5000. That's 49995000 people who haven't needed the properties dialog enough to download it as an extension. Essential functionality, huh?
1. It's really difficult to find this add-on, because once you upgraded Firefox you don't even remember that option name. Can you contrive a Google query which leads directly to this web page without using words "elements properties extension"? Most likely you will hit the bug report which discusses the loss of this option but then you should read all comments to find the extension name.
2. Most people use Firefox for a) Social networking b) E-Mail'ing c) Reading news d) Online shopping - none of these activities require any understanding of a web content. On the contrary most web developers and advanced users often need to examine web page element properties - and why most of them haven't installed this extension - see point 1.
3. I have to agree that most people don't need this extension/feature, but it doesn't mean that Firefox developers should drop features without creating an extension which substitutes for the loss of existed functionality, because in this case you can get rid of extensions mechanism because most users don't need extensions at all. Yes, you've read it right - most casual Firefox around me don't have a single extension installed.