Good idea, but a lot of these feel like saying the professional way of telling someone to eat shit and die is “consume fecal matter and perish in an inferno”.
There are some here that are okay, but a lot just shouldn't be said (like "I told you so").
If I told someone something and they ignore it, potentially even multiple times why should I not say it?
Maybe you're fine with the likely outcome. But maybe not.
* And there’s a distinction between what’s likely to happen and what you think should happen. They’re not always the same thing.
If you make a prediction correctly, and it is ignored, then that's an indication that you should either make it more assertively next time, or you just can't work with this person.
And anyway, some humbleness is due -- sometimes we think we've given good advice, but it ends up being somehow inapplicable to the problem for reasons that are outside our scope.
- Remind them next time it's relevant - "Remember last time we touched this service and the Widget crashed and took the rest of switch down with it? I think this could be similar and we should reconsider my plan to isolate the network before hand."
- Mention it to your manager. Failing to heed a warning can be blameless and rational, but if you're consistently right when others aren't that's a sign you should have more formal influence (and responsibility). You won't get that by complaining to peers.
- If it was extremely serious (it rarely is - the really bad stuff is usually stuff no one foresaw) and your concerns dismissed out-of-hand (also rarely the case - people legitimately have different priorities), discuss it with your/their manager.
You can also of course do it if there is no other escalation path - CEOs and EMs ideally didn't get where they are by being unable to take criticism - but you should also be very sure your advice really was right, and not a stopped clock.
I can still tell you're being an asshole even if you write in business English, so can others who read it, and no-one is giving bonus marks for "professionalism".
I've worked in the UK and in Germany. In the UK there's much more of a tendency to use roundabout phrases to get across what you mean, much like many of this site's suggestions. In Germany, people tend to be more abrupt. Both registers can be just as kind and supportive, and just as cutting and destructive. But either way, there's no magic politeness spell you can cast that stops you from appearing to be, like the parent commenter says, an asshole.
OP's site adjusts the register to something more polite.
The confrontational statements are still confrontational when phrased more politely.
LATIN: Stercorem pro cerebro habes.
WHAT YOU SAY IT MEANS: That's certainly food for thought.
WHAT IT REALLY MEANS: You have shit for brains.