It can be kind of irrational. If toothpaste waste is important to you, there are better ways to avoid it. My local no-packaging store, for example, sells toothp

It can be kind of irrational. If toothpaste waste is important to you, there are better ways to avoid it. My local no-packaging store, for example, sells toothpaste tablets, completely without plastic or packaging of any kind (and I'm sure you could buy something similar online in bulk with minimal packaging). The effect on waste production that using the last few drops of every toothpaste tube will be negligible compared to the use of a waste-free or waste-minimising alternative, but I get the impression that a lot of people do the former without trying the latter out of a misplaced sense of utility.