I asume that's due to his insight in the germany industry at general. I'm german and I don't see that neither. I try to explain that, at least a little bit.

Germany, despite being technologically strong, is not very inovative. At least not in the sense of new, scaling products. One of the most famous examples is MP3. Also, Germans in general are quite risk averse. And if new companies are founded and are successfull, they tend to end up in the mittelstand model. While that indeed is one of the cornerstones of the german economy, these companies are most of the time too small for an interessting tech IPO.

Yet another reason is the way the german industry is structured. We are very manufacturing driven, which extends all the way back to education. And manufacturing companies is what the german economy wants. So, if a start-up devlops a new way to manufacture, say, ball bearings there are basically two outcomes.
They either find enough investors to built an own construction site and / or the necessary structures to outsource production and sell to the various industrial customers. That's expensive, especially compared to the archtypical SV start-up, that's risky which drives of most banks and goes against the common risk aversion and takes time and people. People, again, are hard to come by since most tech people (read: engineers of all colors, mathematicians, physisits,...) all want to work for one of the big names instead of a small, newly founded company. More on that and education later.
The second outcome is that they either get bought by some existing company or the patent is liscensed or bought. In this case it doesn't really matter wether the product in question actually the light os day or not, the company simply doesn't IPO.

Finally, what in my opinion makes it very unlikely that a company has a sucessfull tech IPO in germany anytime soon is people.
There's education, focusing on producing people for the existing technologies and, even worse, companies. Some universities have programs for entrepreneurship, but these programs are small, young and mostly producing start-ups that end-up aquired. But it's at least a start.
Another problem start-ups are facing on the people side is that most students in technical domains want to wrk for, say, BMW or Audi. Meaning these companies can pick the, at least in theory since there's always the chance of missed talent, the brightest people leaving the rest for the smaller players. And for a start-up to succseed you need the brightest (try to beat BMW here).
Finally, failure and unemplyment carries a certain stigma in germany. So once you tried a start-up and failed in terms of future emplyment you are facing two major problems:

- You failed, by definition that's your fault and we don't hire losers (slightly exagerated)

- You have been your own boss for a while, which means you are unable to work under a boss. We can't need people like that.

And finally, German engineering and technology tends to be over engineered. And the shows in all aspects, be it tech, processes, products, you name it. That's great for existing products since it usually produces quality (if this quality is actaully needed or not is completely different question). But that also makes things like a MVP very hard to built and almost impossible to sell in Germany. And why building something in a market you can't sell to.

That's my take on why the author and I see a (major) tech IPO out of Berlin unlikely.