Hambini is an aerospace engineer for Airbus as far as I know. Bottom brackets are just a small side business. Leuscher for sure is more biased towards his business of course and only sees the problem cases. But still its hard to argue with some of crap they show, e.g. the latest Cervelo headset design is such a basic design brain fart its hard to excuse in 2020.
Being in the bike industry because people like it is not really and excuse for poor quality is it? I would argue that is exactly the problem. I would also argue the top engineering graduates have less desire to work in the bike industry than aerospace or motorsports for example even if you’re into bikes. I know I never considered it as an option. People end up there because they like it, often without the proper academic background or experience. How else would you see such designs like the Cervelo one going out? Any design engineer with some knowledge on composites would say its bs.
I don’t mean to be cynical, just realistic having some understanding on the topic. Most of the time the engineering & manufacturing is just adequate for the average cyclist. They will never notice if the carbon layup is bad or if the tolerances are off, they are just happy its made of carbon. It’s probably even safe under the average user. Problems appear when you have a crash or put the bike under some other extreme use case / racing etc.