Deleted scenes are a natural part of the TV-making process, and Doctor Who is no stranger to them. It's a show that has to cram countless big ideas into an extremely tight runtime, and so, at a certain point, that superfluous joke or that extra bit of dialogue just has to be removed in order to keep the plot moving at a brisk pace.
And while the majority of Doctor Who deleted scenes are unnecessary bits of fluff that aren't really important, some are a lot more substantial, and if they had been left in, they would've even made certain story beats a little bit clearer.
We're not saying that these episodes are total narrative trainwrecks, but they do each have a deleted scene (some that were shot, others that were cut at the scripting stage) that would've shed more light on a potentially confusing issue, whether it's an odd decision that a character made, or even a problem with continuity.
So, to quote the Cybermen, maybe hitting "DELETE" on these scenes wasn't the best option, because they all contain information we would've liked to learn in the actual episode.