1. "Killing adoption"? For what goal? People have different thought process, each dialect will be more natural for a certain subset of people. Offering dialects and diversity in choice is a good thing. I have only limited experience, last semester when i graduated i took a SICP course and now i have read through On Lisp because i thought macros sounded powerful, so i am going to be programming a hobby project in Common lisp. But that doest mean i want Scheme to disappear from the world.
2. Libraries.
3. I haven't used CLOS much so i can't really say anything. But making complaints that things are "bolted on" Common Lisp because of the macro system seems to me that he has missed the point of what people like with Common Lisp and its macro system.
4. Can't one use Scheme if one wants portable hygienic macros? I can agree somewhat with the macro situation and my own research seems to point this to the historical decision to pass on fexprs to gain efficient compilers. The plus side is that macros can expand macros means is generally works. And i don't get this "band-aid" notion. From what i understand macros are argument to use lisp and should be utilized.
NewLisp offers fexprs and is focus on interpreted, which means that at any time you have access to a functions definition to use for self-modifying code and eval is blazingly fast compared to other lisps that support compilation. I want to start experiment with true ai that can modify its behaviour in newLisp soon. This is also an argument on point 1 of the diversity of lisps. ( yet i guess you could in common lisp use a macro that always saved the interpreted function definition in some global has that you could operate on in a macro dsl )
On a closing note i would like to add that it isn't really important to attracts people to lisp. Infact from an ethical standpoint trying to sway people which tools they "need to use" is questionable. And in a similar spirit of the HN article "People don't like creativity" i am not convinced that everyone actually would prefer lisp even if we lived in a world where lisp were as popular as C# and Java together.
Every programmer will hear about lisp at some point and if they are interested in it they will probably explore it.