On the topic of the Update Manager:
Some distros don't offer upgrades at all, and some distros offer you to upgrade everything blindly.
We identified the following facts:
- When an update is important, we should make sure you're aware of the risk associated with not applying it.
- When an update can go wrong and break your system, we should make sure you're aware of the risk associated with applying it.
Now, as much as some of you would like for the World to be all black and white, well ... it isn't. We're not going to hold your hand and recommend something that only you can decide. Can we afford to pretend all security updates are safe like Ubuntu does and end up with novice users unable to reboot? No, certainly not. Can we afford to bypass anything potentially risky at the cost of not recommending security updates? Well... there's politics involved here, and we've been attacked by our competitors in the past on exactly just that. So no, we can't do that either.
The cold reality here is that some packages are so important within your system, that if a regression is introduced in their update, and if you're not experienced enough to troubleshoot it and re-downgrade you might be in a situation you can't solve. And sometimes, some of these risky updates will also address security updates.
So I'm sorry. I know what you want... a big red sign that says DONT TAKE THAT ONE, or a nice green label that says JUST DO IT. It isn't like that though. If you know anything about security and development you'll understand that it's all about information. Read the changelogs, see what the updates fix, browse the forums for signs of regressions, and make the decision yourself.
If you don't have time to go through updates and assess what they fix and what risks you're taking when applying them, then either apply nothing or everything, but don't blame the tool for putting the decision in your hands.
Sorry if that sounds a bit rude. We've the best policy out there on security vs stability, we don't send users in the wall with a comfortable "click here to dist-upgrade" upgrade tool so it's very frustrating when the rationale is ignored like that and we get flak for not making it trivial for you to break your box.
I'll give you a hint: Regressions happen all the time. Critical regressions are quite rare. Security updates come all the time, security updates you can't do without are quite rare. So in practice, if you upgrade everything blindly, you'll get fixes, many of which you don't need, and a few new bugs, most of which won't annoy you too much. You will take a risk though, and if you're experienced enough to fix things from tty, switch kernels, downgrade packages.. then that's ok. Because on the rare occasion where an upgrade crashes your Cinnamon DE, or worse.. your boot sequence, you'll know what to do. And in practice, if you just don't upgrade anything ... ever... well, you'll keep your security holes, many of which won't matter to you (I'd like everyone to think of the last few security holes they patched on their system and try to find out what that changed for them... in practical terms), you'll keep some bugs that were fixed, and your system will continue to be "good" whereas it could have been "better"... you don't take the risk to break it though. So there you go... as you can see, you can make the wrong decision to always upgrade everything, or to never upgrade anything... or you can spend some time and do some research on the few package updates we flag as both secure and unsafe for you and rely on levels to get the best of both worlds.
I've read people call themselves "security experts" and indulge in "generalities". I've seen people hired as "developers" denying the concept of "regressions". This is very much a question of trust and information. If you trust us, take my word for it when I tell you this: YOU need to decide what is more important between security and stability, and sometimes you need to make that decision on a case by case basis. Next time somebody tells you to ALWAYS or NEVER do something, understand that this person isn't qualified enough to give you advice.
We're doing our best to make a tool which gives you as much information as possible. You're not a target, security is important in theory but you need to weight its cost. As for development, a good developer sometimes breaks a few things when fixing other things, and often breaks a lot of things when writing new things. A bad developer breaks things just as much, but is unaware of the fact that he does, might, or will. Ubuntu's policy is to expose you to constantly run the latest updates, to take the fixes, and if breaks happen, to send you more updates to fix these as well. It works, but there's a risk. We think it's great for IT hobbyist, but we don't think it's great for Joe user. Our policy is different, we do this for updates which are unlikely to affect your hardware, the lower layers of your system and your boot sequence.
I hope this ^^ helps you understand a bit more why we do things the way we do.