Wikipedia:Do not make problems to prove something
Say your point; Do not experiment to prove it
Talking about problems is better than showing the possible problems that could happen by making problems yourself.
Some people may sometimes get annoyed or angry, muchly when something that is important to them has not been done properly in their oppinion. The person may point out other similar situations which were done better, and this would mean there was an "inconsistency" with Wikipedia, which is a bad thing, because it is a contradiction.
When this happens, the user who is angry may sometimes try to prove their point by showing the problems with the system by making problems happen. This is usually disruptive.
Normally, these edits are seen as a bad thing by people who think they are not very good at helping persuasion. Some people think the edits are spiteful, and that people can get hurt by this. This is why talking about something is better than "proving a point".