I don't really know why people are jumping on you, because you're right about everything you say. The game, like most of the best flash platformers, is pretty utilitarian and obvious. The humor is patently crude. There's no disputing that. VVVVVV and Zeta's World are two examples of games with much better, more inspired level design. It's not as frustrating as Mario Air or IWBTG or any of the other "you must die a million times to be able to succeed" class of games, but some of the deaths are frustrating rather than encouraging.
The thing that you're missing, at least in my opinion, is that the game really has a "zen groove" like the best platformers; it's true that the obstacles aren't really novel in design, concept, or placement, but when you get a good streak going or when you get the perfect muscle memory after fighting a war of attrition with a given level, there's a really wonderful cathartic response, and you can easily slip into a trance playing the game. The short level length also enables a real "just one more level" feel, combining the addictiveness of a good puzzler with the platformer genre. It's also got, like N+, sublime controls so you always feel like your actions directly lead to the outcome you get.
I think all of Danielsans' points about the game's better aspects are true, and all your points are true (I don't think any of the arguments are really mutually exclusive, honestly), although my conclusion about the actual quality of the game is closer to his than yours.