Readability is putting it mildly; do you write your shell scripts using that && style? No? Why not, is it for readability?
I also have a hard time reasoning about && with anything other than the most braindead sequence of commands because: $(thing && if other_thing; then inner_thing1 && thing2; fi && ohgawd)
And I just realized while typing that out that if its parser doesn't support ; then I guess one needs to
RUN if conditional_thing \
then good_luck && \
fi && \
echo "whew"
This is a valid point -- I replied to why this is the way it is here: https://news.ycombinator.com/item?id=43629049. I understand it's not ideal for many, and I am open to PRs!