Or in other words: Why should you tour with historians?
Both of us have spent many years in academia - about two decades in total - but why should that make a difference to you? After all, anybody can open a book, memorize dates and take people around. In fact, most guides in Berlin use ready-made scripts they got from the companies they work for, which might work fine as long as their guests don't ask anything that's off-script.
While indeed practically any guide could tell you when the wall was built or when Hitler was appointed as chancellor, such facts are probably one of least important aspects of guiding. Contrary to the common notion of history as an endless list of facts about the past, history is actually something very different.
Academic historians hardly ever discover new details about the past (although some do). The main part of the work is in interpreting the facts and putting them into the right context in order to turn information into knowledge that allows insights. It is about connecting the dots so the whole thing makes sense. And most importantly, it needs to be done in a way that is relevant to the present - otherwise, why bother?
The great challenge, if one is an author, is to make the past meaningful to your readers, here and now - or to your tour guests, if you are a history guide.
This makes history just as much about the present, in which it is created and debated, as it is about the past, which it conceptualizes and narrates. If historians were artists, the facts would be the painting's frame, making sure the historian stays within reason and tells a well-based story. Facts matter, because sometimes things seem related, although they're not (creating misconceptions). Yet facts alone don't tell a story. The past in itself is not yet history. The centerpiece of any artwork is not the frame, but the painting itself - it is the factually correct and well-told story that makes a difference by making the past interesting, meaningful and relevant to you. Doing so skillfully, is where academic training is important.
If one is only looking for the basic facts and wants nothing more than to check off locations on a list of things to see in Berlin - then academic expertise is probably too much. But if you are looking for a deeper understanding of the story - be it the story of Germany's nation-building or the story of Reform Judaism beginning here - and if you want a meaningful experience and thought-provoking, authentic conversations, spending some time with us is a great choice.