I (like I suspect many people) tend to read top to bottom, so saw it as Google being first - the beautiful but very subtle delicate colour of the years along the bottom axis totally faded into the background. It's a really, really ineffective design
Agreed. And this particular problem could be trivially fixed simply by top-justifying the columns of icons on that slide, so that the list of "providers" for each year starts at the same distance from the top of the slide. That still wouldn't be as clear as the original, but it wouldn't be as misleading as the proposed replacement.
A slide designer he might be, but I have to wonder if he's familiar with any of the actual research (eg eye-tracking studies and visual-comprehension studies), or the relevant theory in any area other than aesthetics (eg visual rhetoric, technical communication).
Of course, no one design is appropriate for all presentations. Audience and occasion should determine slide content and appearance, not some general aesthetic.
When I give technical presentations on our software to customers, my slides are very straightforward: a few short bullet points, a small section of a screenshot, a short code fragment. And they all use the style (font, background, layout, organization) mandated by Marketing at the time. When I present at academic conferences, on the other hand, my audience is rhetoric scholars - hyperliterate subject-matter experts who habitually analyze everything and are there for the theoretical concepts, not specific facts. So my slides are hermeneutic and don't replicate material from the talk itself. There are no bullet points. Some slides are just a few words or a phrase in black text on a white background; some are a long text passage with a few words highlighted; some are collages of text and images. They're part of a performance, to make things a bit more entertaining and less dry for the folks sitting through 75 minutes (3-4 speakers plus Q&A) of arcane discussion.
The corporate slides, which work well for their purpose, would be tiresome in the academic setting; the academic slides would be a disaster at a software user conference.