It does seem like another Olympus has fallen to me.
I feel Sennheiser are too big, of course there's plenty of profit in the enthusiast headphone market. Maybe just not for a giant corporation. Not now anyway. And that is not always such a bad thing. The smaller companies are doing fantastic things, look at ZMF, Hifiman, and others!
Sennheiser made a few mistakes, I feel. No Sony or Bose competitor in portable NC cans. Momentum just wasn't quite it. Flagships too similar, not enough variation or ideas, all the same tuning. It all seemed to end with the HD800. Fine tuning from then on, not really innovating. I have the HD800S and they're technically very impressive but just don't excite me like Audeze, Focal, Hifiman do.
Their neighbours Beyerdynamic are ahead too - Sennheiser have never had a closed headphone to compete with the T5 range and don't really offer anything around 150 euros to compete with 770 or 990 either. Yeah ok HD-25 is fine and has sold well in professional fields, but it's no like-for-like DT770 is it? And very uncomfortable for longer sessions.
It just seems to me there are a lot of HUGE gaps in Sennheiser's strategy and product line up.
Besides, it has become clear China is huge price competition in the consumer market, dumping such highly specced stuff at minimal profits (or even as loss leaders) onto Amazon globally! Gone are the days where you can sell a mediocre IEM for $500 when Chifi IEMs exist on Amazon for $70.
Sennheiser should probably go ahead and completely sell the division, license their name, keep it in Germany and go on an engineer recruitment drive to make some great artisan cans for a niche of music lovers. Whoever runs this new division can probably give up on the consumer market and just go for audiophiles instead. Or simply allow Neumann and their pro audio division to market new stuff to audiophiles and music lovers?