This is not strictly correct, tracking does help as the numbers from the DOE calculator show. However, the cost of purchasing, installing, and maintaining a tracking system will cancel out some, or possibly all of the gain. How much so is not clear.
In this case, a 4500Wp fixed angle installation, which appears to be available for around $12,000 not including installation or installation brackets generates 4364kWh per year in Seattle, saving the homeowner $279.30 in annual electric costs given the alleged 6.4ยข/kwH rate in Seattle (which seems very low to me). This is equivalent to a 2.3% return on the investment, with, unlike in savings, the principal is non-recoverable and expires after 25 years as the panels reach their end of life.
The numbers are better for other cities true. The DOE calculator gives 5491 kWh/yr for a 4500Wp fixed angle installation in Hawaii, with 18.1 cent electricity. Over a year, the electricity value is $993.87, an 8.2% annual return, but again, with the principle not returned and the investment expiring after 25 years.
Given the rate solar PV panel prices are falling, however, PV in Seattle-type climates (and in Germany like the OP discusses) may be economic much sooner than many people expect.