It's not something unique to reddit, even classic forums will often have a self promotion section or thread, Discord servers will often have a self promotion channel. HN has a guideline against posting your own stuff too much.
Spam is a problem and has been since the dawn of the internet. Efforts to limit it will always affect innocent people to some degree but it's not really feasible to not do anything. And reddit especially has an astroturfing problem since it became such a popular source for recommendations. Like, just looking at GP's profile here kinda adds some context as to why they might say this change makes reddit useless to them.
Spam is a problem and has been since the dawn of the internet. Efforts to limit it will always affect innocent people to some degree but it's not really feasible to not do anything. And reddit especially has an astroturfing problem since it became such a popular source for recommendations. Like, just looking at GP's profile here kinda adds some context as to why they might say this change makes reddit useless to them.