The parent is 100% right. It's sad that this kind of attention whoring and flat out wrong stories make it to slashdot. So let's take the points one by one:

• The new theme is too bulky, inconsistent on different platforms, and inferior to the highly refined and very user friendly theme of 1.5 (this is despite late efforts by Mozilla to spruce up the icon set and improve consistency) - You're joking, right? The top one reason why you don't use FF 2.0 is because of the theme? And just to clarify: there were no major, radical changes in the look, they swapped just some icons.
• Antiphishing technology is both weak (blacklist based) and a potential privacy problem. The privacy issues are raised because Firefox 2.0 Antiphishing Features employ an engine previously released by Google, which has been shown to potentially cause privacy risks. - Now this is flat out wrong. If you look in your settings you'll see that there are two possibilities - download a list periodically and check against that (which is no privacy risk whatsoever and is the default one selected!) and check for each page with google (which is the alternative and by default not selected!). I agree that a blacklist based approach is not 100% perfect, but it's better than nothing.
• The new Options dialog box is confusing, poorly designed, and illogically hides important features - my guess is that you didn't look in it at all since you would have seen the options for phising check (see the previuos point). And again it's 95% the same as in 1.5
• There are many reported compatibility issues with the large existing libraries of extensions, themes, and plugins currently avaialble for earlier versions of Firefox. While this can, to some degree, be expected, the loss of this huge user contributed extension base is a non-trivial problem with Firefox 2.0, and could be a deal breaker for some people all by itself - propaganda with not supporting facts! What percentage of the extension is incompatible? I guess you don't know! How many extensions didn't work for you after you upgraded? You don't say! Have you upgraded at all and checked this things for yourself or are you just talking BS to get slashdotted? My experience is that out of the 17 extensions 3 were incompatible, however they are not essential and probably will be upgraded in the next few days (I could force them manually to load, but I'm lazy). In fact I've just checked and one of the extension is already updated, which makes 2 out 17!
• The well known memory leak issue, which causes the Firefox browser to consume ever increasing amounts of RAM, eventually leading to sluggish performance and crashes, has been carried over into yet another generation. This is despite an enormous amount of public commentary and user requests for resolution prior to release of a new version of Firefox - Any proof? I use the leak watcher extension for FF and since I've upgraded it found no leaks at all (it used to pup-up every couple of minutes in the old version).
• There are reported problems with the CSS engine in Firefox 2.0, affecting various websites, and making certain features unavailable to surfers. Notable among these is a continued problem with certain aspects of Yahoo! mail - What problems? FF 2.0 is one of the most compatible browsers out there. Of course that those "IE only" websites with proprietary non-standard stuff don't work but neither did they in previous versions. And I use Yahoo Mail daily (the new beta non the less) and it works just fine.
• Reports indicate that episodes of random freezing during use are worse with the 2.0 version, though a cause has not yet been isolated - it doesn't freeze for the 99% of the users and hopefully it will be fixed for the 1% (which should make bugreports on bugzilla)
• Numerous users have reported that the History bar is buggy, and that in some instances - for unknown reasons - will not display recent items when the history menu is opened as a side panel - again, see the previous reply. Also the forum the link is going lists exactly ONE person complaining and the others trying to help him, which by no means counts as numerous users.
• RSS feed handling has taken a step backwards, and is inferior to that of IE7. - Exactly in which way? Giving no specifics is great for attention grabbing but does not add anything positive to the discussion. And btw, the fact that now I can add my feeds directly to Google Reader from FF 2.0 is great and by no means a step backwards.