Not a single bad issue in his run. Not many about whom that can be said. Lee-Ditko certainly, no bad issues (well maybe that Looter one near the end).
Well you bought it cheap then I guess. I shelled out a fair bit for this issue because it has now become a classic collector's item.
It's purely subtext and obviously it depends on fans connecting the dots, since I don't think Stan Lee or Ditko were entirely conscious about this when they wrote and created this character.
But let's ask,
-- What is the main purpose that Jonah serves in Spider-Man's story? The answer is that he makes the public disapprove of Spider-Man, and gives him bad publicity.
-- Now the second question is, why is it important for Jonah or a character like him to do so, to turn the public against Spider-Man? To always have him defending himself, to always yearn to prove and vindicate himself? Why is it important? What is lost and gained if this element were not there?
Because from a plot perspective in AF#15, Peter Parker gets the lesson of "great power there must also come great responsibility" and he learns that he's not perfect or good and he learns the price paid for the vain pursuit of fame. He decides that he will set right and become a superhero. Then in TASM#1, the first issue of his flagship title, Jonah appears and launches into his crusade against Spider-Man. Basically Jonah is an external manifestation of Peter's internal guilt. Peter will never forgive himself about Uncle Ben and he doesn't think he's entirely a good guy, well here's someone on the outside who thinks that about Spider-Man. So basically neither Peter nor Spider-Man can take anything for granted, they have to always prove themselves and are held to a high standard. And Jonah is the guy who does that. Jonah in Peter's life is "Part of that power most misunderstood. Who always wills evil, but always does good".
And Chip Zdarsky's landmark "My Dinner with Jonah" kind of made this canon. In an additive retcon (i.e. a retcon that doesn't contradict anything previously established), he put Jonah in the audience when Spider-man made his debut on TV. So Jonah, like Mary Jane, knows Spider-Man before Spider-Man:
Attachment 92211
So Jonah now has reason to believe that deep down Spider-Man was always a clown and showman out for publicity. Because that's the first thing Peter did when he got powers. Did Peter subject his blood to the scientific method and publish research papers? Nope. First thing he did was become a superhero Justin Bieber. Which I guess is better than becoming a school shooter or taking over the world. But it's not exactly someone you would think of as capable of heroism. You would think that guy's first instinct is for wealth and fame.