I think it is the seedy vibrato that is the icing on the cake. Similar examples would include "Memory" from Andrew Lloyd Weber's Cats:
The Empty Épater: This is when the composer, in defiance of any aesthetic whatsoever, simply sets out to annoy the listener with various kinds of random unpleasantness. This was John Cage's specialty, but others who indulged included Karlheinz Stockhausen, Mauricio Kagel and Sylvano Busotti. One nice example:
The Long Goodbye: This was the name of a slow-acting poison on The Game of Thrones, but I think it also describes quite well those pieces of music that wear out their welcome. Oddly enough, it is not through a paucity of material--Haydn showed us hundreds of times how marvelous music can be made from the most limited material--but through the dreary repetition of material, the choosing of tiresome material and just by going on much too long. I know that this will incur the wrath of a certain Canadian commentator, but my thoughts go immediately to the Symphony No. 1 by Gustav Mahler where never has so much been made of the perfect fourth for so long:
An alternative choice might be the Symphony No. 1 by Bruckner.
The "More Cowbell" Syndrome or the "More Trombones" Effect: This is when the composer, for want of any creative spark, just decides that more is better: more percussion, more brass, bigger orchestra and, in the final stages of the disease, multiple choirs. The locus classicus, again, has to be Mahler, the Symphony No. 8, but we might give honorable mention to the English composer Havergal Brian, who contracted a bad case of Mahleritis. So here you go, Mahler 8 and the Gothic Symphony by Mr. Brian:
Also, for the visual effect, part of a Proms performance of the Brian symphony:
Those seem to be the main categories of aesthetic awfulness, but perhaps my commentators could either add some more categories or more examples?