Bureaucracy. But thats the main problem in all industries...
Also Crysis and FarCry are German (or where fir FarCry) Anno is also a thing Germany made. Its just not at all profitable to get big in Germany, things that sell get sold to other publishers.
It's not like Belgium does anything special either for the games industry. Their success is just due to hard work and good management by a studio that's taking the long term view and it's passionate about the work.