Just my 2cents: It costs additional money to install a kitchen in a newly built house. The company or person who buys the apartment will try to avoid the costs. If they install a cheap kitchen possible renters might say that they would like to rent, but the kitchen looks too cheap. If they install an expensive kitchen the rent will be higher. So they leave the kitchen empty and the first renter can buy a kitchen he likes. If he has to (wants) move to another town he has two options. 1. selling the kitchen to his successor - and getting only 20% of the costs of the kitchen or nothing if they already have a kitchen. (+ buying a new kitchen of course) 2. take the kitchen to the new apartment and adopt it. Normally you can still buy parts for a kitchen if it is less than 5 years old. Option 2 will definitely be cheaper.
In 2002 we moved into a new apartment (without kitchen) so we bought an
Ikea kitchen. In 2004 we moved into a larger apartment with a horrible dark kitchen. We asked the landlord to remove it (using a sledgehammer it took less than 30mins) installed the parts from our old kitchen and bought additional cabinets.
If you only live in Germany for a short time it can be fairly expensive. However, remember that expats are only a minority in Germany.