You know, bad habits get kind of a bad rap... But I've found that some bad habits have occasionally been what's needed just to keep me going. Like for a while, I almost totally stopped prepping my skin with alcohol before shots. But OMG, I was so completely sick of shots at that point! But that bad habit, which I knew plenty of other veteran diabetics did safely enough, made the shot process more tolerable during that difficult phase... and I got back on track before too long.
And then, there was when I got way sick of spending so much time doing test after test! I stopped properly washing my hands or cleaning my finger before hand and resorted to just licking it and wiping it off (maybe marginally better than just sticking your dirty finger). But at least that kept me testing, and now that habit is gone as better control and my Dexcom have helped reduce the "extra" tests and as I've learned better shortcuts (like dunking the finger in a glass of water instead of licking it, or rubbing soap and water between just one finger and my thumb if I want to take less time and mess than a full hand washing).
So while breaking them is advisable, don't always knock the bad habits, especially when you see them in others. Maybe it's an alternative to a much worse habit... like not injecting or testing at all!