It's not the opinion per se, but the trend of talking trash about Comic Sans that's tiring. People who have been in the business for more than a few years have seen this joke done and redone a hundred times.

Dissing Comics Sans is an elitist, designer-only inside joke, and I'd guess usually perpetuated by young designers. It's saying "This thing is immensely popular, nearly ubiquitous, but now I am part of the select group that knows that it actually sucks."

Comic Sans was born in the context of a particular project, a particular set of constraints, deadlines... being able to understand why it is like it is, is already an exercise in undestand real design. It then became immensely popular among the myriad of fonts pre-packed with Windows. If you think about why it did so, there are things to learn about users of an operating system / office suite, their needs and wants. If one wants to consider oneself a good designer, it would be better to think about that, rather than indirectly make fun of your mom or dad or cousin or other non-designer users for liking Comic Sans.

And as for the joke in the app, other products have already done the same thing (can't remember exactly, but some SaaS thing for designers would go full Comics Sans if you expired the trial). There were tumblrs dedicated to changing everything from move titles to book covers to famous logos to Comic Sans.

So if you've never seen that joke before, it probably just made you giggle. If you've seen the other dozens (hundreds?) it just makes you sigh.