Is that it's lazy and clumsy. Yes, I use it sometimes. Sometimes I am lazy and clumsy.
It allows a writer to make a strident statement e.g."Xxxxxx Xxxxxx is the biggest cheat in F1" and then retreat behind the initialism "IMHO" as though that softens the blow. It certainly does nothing for the tone of a sentence.
Compare with "Based on what I've seen in that race, Xxxxxx Xxxxxx is a cheat"...
And I completely agree with you categorisation of what is not an opinion.
Though, power is measured in kW and 0-62 isn't impressive if it's in km/h...IMHO.and anyway is it SAE or DIN power..etc etc .
Maybe the next head-scratcher should be on pedantry....
or the use of smileys to offset curmudgeoniness