Carl Spitzweg was born in Munich, Germany on February 5, 1808. He died on September 23, 1885. As a young man he worked as a pharmacist. In 1933 he received a large amount of money and suddenly found himself to be independently wealthy. He quit his profession and became a full time artist. He had some experience with drawing, but had never had any formal training. As far as you question is concerned, Spitzweg sold over 400 paintings and was very popular with the middle class. There was some disappointment over the reception of the first version of the “Poor Poet.” However, he redid the first version and the second painting is considered one of his best. He painted humorous scenes of people in funny situations and he also painted landscapes. I personally have never found any of his paintings to be ugly or horrible and could find no such criticism.
"He was provincial in his choice of subjects and is an outstanding representative of the Biedermeier style. His pictures are generally small, humorous in content, and full of lovingly depicted anecdotal detail."
As you may already know, Spitzweg is a representative of Das Bierdermeier. This style you can catch in many beer stein mugs, and even in the Lobel figurine collections. They consist on the bucolic or pastoral scenes in deep reds and blended yellows on a dark background.
The characters are often depicted in a satirical way, often old people with wide-open eyes, and weird looking mouths. Their eyebrows are always weird-looking with a tense expression in them. The characters are always in-task, arguing, talking, in action.
From this description you could judge which paintings would be considered more satirical than others. One of them could be the Das Jagdunglück (The misfortune) and Aschermittwoch (Ash Wednesday). I personally do not like those, because they deviate a lot from The Bookworm, which is my all-time favorite and Der Ewige Hochzeiter.
Personally, however, I would have a hard time considering any Spitzweg horrible. Just performed in a different style.