So many people take exception to burning religious texts, and I can understand this if it was the only remaining copy of the text and the knowledge would be forever lost if the book was burned.
But at the end of the day, these are books that were printed, often for money, by publishing companies and are simply copies. Unless you're an environmentalist protesting the waste of wood pulp and the cutting down of trees, is it really worth all the hullabaloo?
All of my scripture is on Kindle, so if you were to burn my iPad, I could just get on another device to read it.
Are you talking the simple disposal of sacred texts or objects because they are worn or broken? Or are you talking about making a public statement, either about your own past religious texts, i.e. the Ex-Christian atheist either burning his old bibles, or throwing them into the toilet, or stamping on them with their feet, and such, or those of others?
If you are talking about the former, simple disposal of old sacred objects, then that depends on the person and what role or depth of faith those objects were imbued with. If someone used say a mala for many years and it fell apart, generally they might choose to do some form of ritualized disposal of them, because they carry a sacred significance to the practionneer. Same thing if they revered a book of sacred scripture. To simple toss it aside with disregard would be somewhat tantamount to taking a "oh well" attitude towards their own faith.
In the latter case, say the Ex-Christian, Ex-fundamentalist atheist who had been spiritually and emotionally abused by religion, where God was made the villain at the door who threatened them and psychological tormented them, i.e, the God of Fear, then taking religious objects and burning them is also a ritual in itself. But the purpose of that ritual would be to attempt to reclaim power that was taken away by them through association with the objects of symbols of his previous tormentors. It too is a symbolic act.
This is the nature of iconoclasm. This also applies to urinating on or burning the texts of other religions than their own, who are seen as threats to themselves or others. But the motivation still comes from the same place, to make a public statement through a ritual action that carries meaning to both the doer and the witness of such acts, like flag burning, and so forth. Are those helpful ultimately? That's a different question.