Dreading Diversification? Don't

Writing venues come and go; be it websites, magazines or publishers. Topics become uber competitive or obsolete. Freelance writers get this. We talk endlessly of eggs and baskets--diversification pontification at its finest. Yet many of us dread actually doing it. We shouldn't, but we do. Why does diversification make so many of us apprehensive? Fear of rejection (so they say, 'no'. Next!),