Some people don't read the print at all, probably they thought there's a bag especially some auction title has the word "bag" on it~
Nah, I don't think it's too decieving myself, he/she keeps mentioning dustbag and even says its for a dustbag via the question near the bottom.
The auction doesn't look deceiving at all, it is actually quite clear that it's only selling the dustbag!
Had a problem, but resolved very quickly!