I ask myself the same question, I really do. It is not the easiest play to understand and digest, mostly because of the multitude of ways you can take the piece. Is it a tragedy about a failed rise of the ordinary classes at the time of the Englightenment and at a time of potential revolution? Is it a play about human nature, weak as a reed, apt to grasp at power? Or, is Lessing's Emilia a piece about the subjugation and objectification of women - a concept certainly not widely put down on paper in 1772!
The answer is, of course, that the play takes a little from each of these pots.
I find the play a fascinating insight to the author. Everything is concise, there is very little room to chop and change the play as it stands, simply because the text is so efficient. Other than some colorful flourishes, the text is very clean and crisp. However the motivations behind the words are anything but simple. It is very much an 'actor's play'. The strength of this piece rests on the decisions of the actors about the character's motivations and, to a certain extent, the Director who looks to solidify how these can come across successfully.
Scholars refer to this play as an 'enigma' because there are so many interpretations possible and I suppose that is precisely its appeal as a dramatic work. There are no rules to this piece, and each production of the play may leave audiences with completely different understandings of what the author was intending to portray. Such an ugly end can provoke many reactions.
We may not be German, or producing the play in the German language, but we understand this as truly the birth of modern European theatre and we hope to put together a cohesive story that leaves our audiences guessing. After all, it is not the play, nor productions of the piece, that have come to give this play its notoreity, but the many ripples of reactions it provokes.