But shouldn't they aim to make better movies with each try? They should IMO, and TDW and IM3 were average at best so I wouldn't say high quality has been achieved with all of their movies. In fairness, they haven't made a bad movie yet, but they haven't made a truly great one either. Yes they are very successful, but AOU's BO dropped from the first movie and the home sales haven't been great either compared to the first. The drop in quality is a reason for that IMO.
No one is asking for drastic changes, but toning down the humour in serious moments and giving us better villains could improve their movies, a lot, in some cases.