In September the number of companies will be increased to 40. But even then, when you compare it to popular US indices like to SP500 or even NASDAQ100 you can already see by the number of companies, that it is still tiny. The market cap of DAX30 is roughly 1 trillion $, while the SP500 has about 35 trillion $ in it.
In my mind if you want to invest into Germany, you could buy HDAX, which also includes MDAX and TECDAX and at least consists of about 100 companies. Unfortunately it is not at all popular.
Germany just has very little publicly traded capital, partly because of the privatly owned Mittelstand, sometimes resulting big corporations like Freudenberg, Bosch and others still being owned by a family or a foundation. Both of them would easily be included in the DAX.
The other problem of course is totally missing out on the whole IT thing.