In my opinion, which may be different from any school, Śūnyatā / emptiness is a beautiful misunderstanding, or a dazzling over-interpretation.
You are probably wondering why a thing so simple as emptiness or nothingness can be too much.
As I know, when people are adventuring in meditation or drugs, they can get all kinds of special even unique experiences which could make them believing they are reaching the core nature of truth or reality.
From my view, what they are near is the unknown (the ultimate secret hidden or concealed by what we see or sense or experience, including by the sensed emptiness or nothingness like space), the ignorance.
Zhuang Zhou once said that what we know is limited, no matter how much you know, what we don't know is always unlimited.
Actually we are so ignorant, even a guy so smart like Zhuang Zhou seemed that he didn't realize that he doesn't know what we don't know is limited or unlimited.
What is really unlimited is our imagination.
When we're facing The Unknown due to some drug or meditation or other stuff, it is like we're facing darkness.
It is easy for us to imagine there is an unlimited emptiness or nothingness like space our there or in that darkness.
And because of the drugs we took or we produced ourselves naturally in our bodies, we could magnify this imagination to some extension. So much so that we lose the distinction between imagination and reality.
There is no shame in it. Because nearly all of us are doing the same things, with or without the drugs. For example, none of us has ever actually seen the space or universe, what we are seeing is always a flat two dimension picture, moving or not moving, we're using our imagination to create a three dimension "reality" in our mind, in this "reality", all lights (optical lines) are straight. Seldom of us realize what is really straight or simple is our logic (Logic is imagining with reason. Reasons are straight, simple rules some people loves to follow like fools, they are so foolish that they call these mind bindings or blinders as intelligence.)
In my view, Nirvana is so tempting because people are eager to grab a liberation from anxieties and other sufferings.
And in our imagination, with or without logical reasons, emptiness means we can finally escape from our selves.
But is it really a non-self? If there is no self, no you, who is there? Who is there admiring this emptiness?
What you lost is not you, but body, thoughts, or other id.
They are not the real you, the true you. Neither are the special spiritual experiences including state of no thoughts, state of no senses, emptiness, nothingness, others whatever they are.
None of the things before you are the real you. The true you is always there, but you can never make it show itself before you. It is like you can never lift yourself by pulling yourself 's hair.
Thus if Nirvana means you can see the true core nature or the real source of every things, it is a legend, or fairy tale.
If Nirvana means you can get the great escape from yourself, it is an impossible mission.
It maybe seems too cruel. Not all of people are grown up, a lot of people need a shelter, (Even a grownup cannot appreciate all the dark moving pictures.) so all kinds drugs (both physical and spiritual) are still popular.