A 'safe space' is defined as 'a place intended to be free of bias, conflict, criticism, or potentially threatening actions, ideas, or conversations'.

The inclusion of 'criticism' as one of the things prohibited in a safe space pretty much encapsulates everything wrong with the concept. Criticism is necessary for the development of a reasoned and nuanced perspective. If no one criticises your views, you will never consider your thought process too deeply, and you will remain unaware of any inconsistencies, assumptions or errors you have made, or any knowledge you lack. Your views will remain simplistic and naïve, and you will not gain any greater understanding.

Banning criticism and 'potentially threatening ideas' (which can be arbitrarily taken to mean 'ideas that challenge my worldview, aims and/or ego') is directly opposed to keeping a place 'free of bias'. Certain opinions will dominate, and dissenters will be shut down.

An echo chamber cannot produce any meaningful discussion. Its members will spend conversations regurgitating their chosen 'acceptable' opinion to each other without questioning it, thus reinforcing each other's misconceptions and lack of understanding. People who think they need such an environment are egocentric, insecure and immature. They prioritise feeling good about themselves over analytical thinking, desire constant approval, cannot differentiate between a critique and an insult, and refuse to acknowledge the flaws in their views or the validity of others'.

An argument in favour of safe spaces is that people should not have to constantly defend their beliefs. This implies that having to justify one's beliefs is inconvenient and uncomfortable. This is not a constructive mindset. If someone objects to your views in a coherent and sedate manner, you should not interpret it as an attack, but as an opportunity to explore why you hold those views and gain insight into both their opinions and your own. If the other person is reasonable, while you may not change their mind, you will probably get them to understand your perspective.

Debate is not harassment, and disagreement is not disrespect. If discussing your beliefs with someone who civilly disagrees upsets you, you are insecure and that is not their problem. This insecurity may be caused by having insufficient justification for your views. If you know that your opinions are the product of conscientious rational thought, you will be more confident in debates.

The idea that 'people need safe spaces so they don't have to constantly defend their beliefs' also suggests that the only way to avoid arguments is to eliminate dissenters altogether, because if someone disagrees with you, you are obligated to argue with them. This is not the case. You are free to not engage someone who wants to debate you. If they persist, then you can make the case that they are being a nuisance, and the best way to deal with this is to continue not to engage them.