Was that a rule though? If you give advice in 100 different meetings, you'll be wrong in some of them for sure, even if you're a domain expert.
If he was the CTO and co-founder it seems that his approach worked well, at least to get him and the company to that level.
It seems like a reasonable product decision given that most people don’t care about typeface history.
But more to the point, for a corporate logo, Arial feels like a cheap knock off to the more polished Helvetica. You can see this yourself, by looking at corporate existing corporate logos designed in helvetica and then redesigned in Arial.
https://www.ironicsans.com/helvarialquiz/
Admittedly this is personal preference in the end, but I feel like if HR is going to give someone bad news, they're going to do it in Arial. If Apple is going to release a life changing technology, they're going to do it in Helvetica.
I guess it would fit your point a little more if I just looked for whichever I thought was more aesthetically pleasing.
Anyway, I got about 50% (accidentally closed the window, I think it may have been 51%?) so at least if I was the customer, the company would not seem to gain any advantage from licensing the superior font.
I think an example of a bad logo is Arial is this one:
https://www.designworkplan.com/wp-content/font-arial-everywh...
The A has too much space around it and it looks "uneven".
The bottom one of this one is Helvetica.
https://cdn0.tnwcdn.com/wp-content/blogs.dir/1/files/2009/10...
It looks "fuller", "denser" to me. And leaves me with an impression of a "sturdy" company.
Finally, here's Neue Helvetica 75 and Arial Pro Bold pages from Linotype. I just open them up in a new tab each and switch tabs to get a better idea for things.
https://www.linotype.com/1264130/neue-helvetica-75-bold-prod...
While I get the point you're making, I remember reading somewhere that successful people (in terms of their career) tend to exhibit less self-doubt.
I remember him overruling the Head of Design and enforcing Arial to be the typeface used for the corporate brand because it was the typeface was present on more computers than any other in the world. Suffice to say the original typeface was much better.
Self doubt is a really really important trait to have as a leader - don't automatically assume you're right outside of your area of expertise and that team members can come up with good solutions that aren't yours is the only way you can ever really scale.
The CTO ultimately was forced out and became a specialist consultant and that probably suited him.