You're right that most people don't know about reverse image lookups. (Thanks for the list, by the way - I only knew about TinEye before this.) I don't think that most people will read the first post enough to get to that list, though.
The intent is good, but you might as well throw in a link to google.com as well, because a lot of people ask questions that could be answered very simply through Google or even Wikipedia.
Why don't people use these tools even if they're aware of them? Part of it may be laziness, but part of it may also be for the social aspect. You connect with others who have the knowledge, you get that personal touch on the information, and the important bits are generally pointed out to you immediately. So, even if the links are added in and people learn how powerful those tools are, don't be too surprised if the same questions still get asked
(On the topic of browser plug-ins, there are plugins to TinEye for both Opera and Safari, as well - just activate the plugin and click an image (Opera) or right-click and select to search it on TinEye (Safari) and you're good to go. Fast and easy.)