Rejected manuscripts, articles or poems always affect a writer. If rejection is accepted in a disinterested way, then the desire to improve and be successful is lacking. The negative feelings will sometimes, however, become too strong. There will be thoughts of giving up writing, or writing to please an audience or niche, rather than to please oneself. Too many rejections will crush a writer, and when depression sets in it's time to take a break and recharge the batteries.
The desire to write will, for some writers, be all-enveloping. It will become an obsession. Friends and family will become less important than writing. For this type of writer, early success or failure will have similar results. It will either drive a writer to even greater heights, or make a rejected writer redouble his efforts to succeed. Being too driven will affect the writing itself. The writer will put so much pressure on himself that his writing will become stilted.
Some writers will let flattery go to their heads. If the flattery comes from loved ones, then there is the danger a writer will fall into the trap of thinking he is better than he actually is. This will end up with a writer not improving and dealing with rejection after rejection. A writer needs opinions from people who are detached to some extent. Blunt opinions will often be hurtful, but they will either help a writer improve or seek a new vocation.
All writers will experience rejection and negative comments at some point. There will, however, be writers who will resent any form of criticism, whether it is constructive or not. Indeed, some criticism will be unfair, and be deserving of an angry response from a writer. But writers should be their own harshest critics and be fully conscious of what merits criticism and what doesn't. A writer needs to understand that few will criticize them out of malice.