From your answers so far, it doesn't seem at-all obvious that were considering disadvantages of "virtual image based systems" rather than particular disadvantages of the ST80 implementation.
Would a Smalltalk image without gui classes not be feasible?
I spent much of my life in an with Smalltalk images (some would say too much), and there were also the big names and figures when I did Smalltalk projects in the nineties. Some of the issues could be handled spending a lot of money. The basic concepts (and issues) are the same in all Bluebook offsprings. You probably mean GNU ST; it has the advantage that there is a compiler and library available outside of virtual images and you can use it like a "normal" compiled language and easily re-assemble a virtual image with the objects and versions required. This allows you to use the image as a cache to reduce startup times like e.g. Dart does it. But this is not the original Smalltalk virtual image idea, i.e. not the "whole environment" the fellow referred to.
I mean that "deploy all development tools used to develop the software" seems to be a separable from "Bootstrapping a virtual image from source code in ST80 is very difficult or nearly impossible".
Would a Smalltalk image without gui classes not be feasible?