Sayyidi wa sandi Mufti Mohammad Taqi Usmani (Allah preserve him) said,
‘My respected father (Mufti Mohammad Shafi, Allah sanctify his secret) use to say this sentence and it must be memorized,
“Censuring on a non-objectionable thing is reprehensible itself.”
غير منكر پر نكير خود منكر هے.
It is inappropriate to do so. This is because when Shariah has not ruled that a thing is impermissible then how can you acting as a (pseudo-) officer (of Shariah) claim that it is haram.
In reality these things are based on understanding the demeanor of Shariah. This is called thorough understanding of religion (تفقه في الدين).
The understanding of the demeanor of Shariah is not solely by reading the (religious) texts. It requires being in the company (suhba, of those who have already acquired this characteristic). It is by this accompanying one ascertains what stand he must take, where to be firm and where to be lenient.’
Inamul Bari, volume 3, page 82-3