Yes but not much of what you say if relevant if we think 1 man, 1 website or just step outside of your dev cave
Renegade probably do not care so much about these features of some framework. He might be interested in easy to use admin panel which makes up huge part of a framework and what you typically do not get from a normal theme. Wooframework and elegantthemes epanel including stuff like shortcodes are the same in all themes, page templates the same (more or less). Woothemes sidebar manager works with all themes. That is why they are considered frameworks but not all frameworks are a like. Semantics
If you find similar intros to Thesis, Headway which are those I have seen you will notice same focus on ease of use via some sort of control panel, just as must targeting newbies. They go after persons who either have little experience or have previously been fighting a theme trying to make changes. Could also be plugins since they are taken care of to some degree. Keyword is EASY not mass production. Somehow they don't focus so much on their own limitations. There might not be many but depends on match between wishes/ideas and framework, much is simply visual evaluation. If Renegade fall in love with elegantthemes but rush out and buy Genesis he is in for a surprise. Does not matter he dream of 50 child themes (all smelling big time of coming from the same mother) and have read on a forum Genesis is supposed to be good with that. Where some go wrong and later return to a more matching solution requiring less studying and experimenting. As you say they, like min. 9 out of 10, have limited needs. Most people value results higher than features they have no need for.
There are quite a few webdevelopers who buy themes for "clients" at Themeforest shop for much the same reason. Why try to make features you don't have the time or skills to do? They modify based on best fitting theme more than develop. Frameworks are not a solution since they do not have the power to produce so different output (much is eyecandy) so in a way frameworks are also fixed one shot solutions. They trap you. Any showcase page will spell that out as well and they are supposed to be top of the pops. You can typically tell what is in engine room, variations of the same - close to more of the same
That they are better for some developers since they can repeat code and their habits, way of thinking over and over is not relevant.
WP is a beast with bugfixing and updates but sure if you are confident whatever you use will get "3.1 ready" as it previously got "3.0 ready" there are no problems or higher risk than with other things in life. But unless you know background etc. for a plugin or a theme you cannot know, only hope. Major problem with those often unknown devs at Themeforest, less with handpicked companies that are ALWAYS mentioned and hyped but still a good idea to check out level and quality of support before jumping in bed with any of them. If foundation for Genesis were wobbling you would never base your development on that framework since you are delivering a product to customers. Will kick your butt sooner than later. Private users have same concerns or they should have.