Answer : There are two schools of thought: one is that people who have been successful in the field interior design "attract" other success because of their impeccable taste. They hang out with successful people, they're invited to galas and openings, etc. These decorators also usually give themselves pretty clear boundaries - meaning they stay within a specific interior design niche and "go deep" rather than broad.
The second camp would argue that good taste leads to success whether or not it attracts anything else: after all, good taste is a signifier of culture and cultural capital. The first school wouldn't disagree with this too much - those designers tend to end up working for other wealthy clients who can afford probably the most expensive designs.