insults are always subjective
An insult is always experienced subjectively (if it is delivered with any effect), but the insult itself is not necessarily subjective. If someone has an IQ under 70, you might insult him by saying he is intellectually deficient, but you would also be stating an objective fact.

So it is with "bunk". It is certainly an insult to dismiss a postulation as "bunk", but that characterization is perfectly accurate if the postulation is merely junk science.

Serious science can never be debunked because it isn't tainted with bunk and it doesn't deserve to be treated as bunk.