I think there is quite some logic in the fact that the exact night isn't revealed. Laylatul Qadr also known as the 'night of power' is said to be better than a 1000 months.
With its exact date not being known to us, we concentrate our efforts into the last 10 days in which we reap the benefits of the blessed month of Ramadan which in itself is a month like no other in terms of reward and benefit. It teaches us steadfastness if we concentrate our efforts over a longer period of time such as the last 10 days, if not the whole month, than if we were to know the exact day in which case we would exuberate all our efforts into 1 day.
We underestimate the lessons learnt from steadfastness, and we pray that Allah grant us this in our efforts instead of the peaks and troughs we see in our own and other's deen.