Just because an app is updated doesn't mean you have to update it. Updates are (typically) a good thing though so you usually want to be on top of them. That means the app is getting support. However I personally hate updating apps so have auto-update off and I will manually update apps when I have to.
As for bait/switch apps, that is solely on the app developer. Complain to Apple about it and leave a bad review. That will hurt the company in the long run and force them to change, or they won't be around very long.
I have over 10 apps published in the app store so I have some experience with the whole process.