There have been some lively discussions about what should and shouldn’t be part of the native toolset. That’s why my hunch is that SU will keep it “as is” (sadly) other than performance improvements. Some think that tools they may not want to use are “bloat-ware”, however, the other way of looking at it is to have the tools but not load them if you don’t want them? It certainly would be nice to have some of these basic extensions as part of SU, especially the ones that are improvements on existing tools. I always reference FormZ as a similar SU program that does have them all included, but you can customize the toolset palette as needed…and as you say, to have consistency in the GUI would be less confusing…
While admirable, building a house with a swiss army knife might be a cool challenge, but after the first year you’d be gagging for some other tools. 
This going off topic a bit and probably merits a thread of its own.
I am sure you are right that developers want to keep a lean basic program and allow people to use extensions to customize. That seems like a good thing in principle. The problem with it is that extensions start doubling up, some work better than others, and there is no official stamp of approval (unless you count the EW).
Having a lean program is the reverse of the AutoCad model, say, where the program is very fat indeed and includes all sorts of tools and capabilities that some will never need, but no ability to customize.
If I were looking for an analogy, I’d say that the current system is a bit like a John Deere tractor to which you fit Massey Ferguson attachments or lookalike parts made in some remote corner of the world because there are no actual John Deere parts!
Your suggestion of having tools built in that can be disabled is attractive for an end user but would it be for a developer, who then has to keep such tools up to date?
(Moved into a separate topic)
I am amazed how far profile builder has evolved, yet I look and try to support dynamic components and find it much the same as when I first purchased Sketchup. Its sad that the native (ruby extensions) tools in sketchup are reluctantly and very slowly improved as compared to other developers. Why should mindsight boolean tools be better than our solid tools? I getting to the point of dropping DCs in favour of profile builder . This should not be so…