Oddly I can see their point...
Normally I would be amongst the mob with my pruning hook1 but I can understand, if the company wrote the code and marketed etc the resulting product, the fact they initially made the source code freely available (FOSS) shouldn't preclude that company from restricting the availability of future versions (here OSS) or even close their source (eg Solaris or QNX.)
The difficult part is when much of the source is from external contributions. Clearly the legal side of this question would have been long settled by the company's lawyers but the ethical/moral side as could be expected is much more difficult.
If, like me, you would only use any source code for personal study or research use and never for any commercial use these licences are infinitely better than closed source. Big commercial users should expect to "support" each other by paying each other's fair non-extortionate licencing charges ;()
With small businesses and startups not directly competing with vendor's particular offering I would prefer that more liberal licensing were offered to encourage product innovation and diversity.
Where the product is largely a compilation of non-encumbered open source external software peppered with the company's own modifications and original code, such a Linux distro vendors, I am more ambivalent with my hand very much on my pruning hook. Here I am thinking of Redhat a company that was very successfully selling support and its profitability can not have been too shabby or IBM would not have acquired it.
1. Commander Vimes had a very healthy respect for agricultural implements in the hands of those skilled in their use ;)