Germans are like that. It's not simply they don't want to ship abroad, they don't want to ship, PERIOD! Also, they don't use Paypal. If you're checking ebay.de, be prepared to get in the car, go to Germany, pick the thing up, and pay in cash!
Paypal had a poor reputation in Germany. Also, the majority that does not accept paypal is either tired of paying all kinds of fees on stuff they sell or prefer cash/bank transfer simply due to the buyer/seller's protection. There are strict rules regarding how the seller has to ship items to be eligible for seller's protection (tracking number for example) and tracking is not available to quite a few countries.
On top of that, shipping abroad is really expensive once an item surpasses 5-10 kg and some are just really tired of the buyer moaning about shipping.
Also, some German fellas on ebay (who sell oscilloscopes and the like) are older folks who don't like the idea of having yet another online account since the online banking service in Germany works well enough for them. Others embrace paypal.
I've had no problems with German sellers so far, sometimes I've even asked if I may send them an email with a DHL postage pdf that will be sufficient for mailing things abroad, even though the auction was restricted as "shipping only to Germany". It's usually just the default way the auction form suggests it for them and never even imagined that somebody from abroad could be interested.
There is a lot of fraud and shady stuff too, and some may simply refuse to take any risk at all.