It's less about the rules and more about the gaming scene that is competitive or less competitive. In my experience, T9A gamers tend to be much more competitive than I am. Then again I'm allergic to competitiviness, especially of the RAW WAAC approach. So I'm probably not the right person to judge how competitive a scene is.
I know of less competitive people who play T9A. But most of the people who want less competition or at least clearer/easier rules from a fantasy game tend to gravitate towards altogether different games.
Similarly, people who like Warhammer Old World tend to choose one of the older editions - be it nostalgia, the right feel for the game, or the availability and interesting game role of units they have readily painted. In this respect, it's clear that T9A supports competitive gaming better than other Warhammer editions, which then again support other kinds of gaming (Old World 'historical', nostalgic/friendly, total destruction, beer&pretzels, etc.). No wonder, since the makers of T9A are mostly ETC veterans, and the top of competitive players from two continents.
In tournaments, naturally, the competitiviness gets to the front. It seems there are not so many T9A players (compared to old Warhammer Fantasy or 40K), so those who want to max out with this game will find their way to the tournaments, making the public T9A scene more competitive.
But who nows how people play in the small clubs and garages?
-Z