If GW cared about tournaments we'd have balance and an incentive for people to play something other than eldar tau or space marines.
They don't care about tournaments. Which results in poor game balance. Which disappoints players. Which leads to lost revenue. Especially since games like Warmahordes and X-Wing with very tight rulesets have been gaining traction for years now. Which is why it's so insane that they don't seem to care. It just doesn't make financial sense.
If they actually just went to the biggest 5 tournament events in the world, took aside the top 5 finishers for each one, said "We'll pay £20 for you to list the top 10 problems you have with game balance in this edition so we can address them next time" then they'd get enough feedback from people who know what they're talking about to fuel the design team for months.
However they seem to be so... scared... of their own customers opinions that they don't bother, and so disinterested in community engagement that they've given up any attempt to cater to or run events for the broad demographics (Painters, Gamers, Fluff fans). Although at least Painters have Golden Demon and Fluff fans have BL Open Days.
Ultimately, I think the only way they're ever going to achieve anything approaching balance is to completely reinvent the game from the core mechanics up, similar to the 2nd/3rd Ed transition. Maybe move to a 2D6 or D10 system. Either that, or realise that "because it's always been like that" is NOT A VALID REASON TO EVER DO ANYTHING AT ALL, EVER.
I think there is too much emphasis on game balance. GW are not encouraging tournaments because that's not the game style they like.
Why are people always linking game balance to tournaments? They have nothing to do with each other. Balance is equally as important to casual gamers as tourney goers. Reducing the number of rules arguments and fundamentally broken units is in the best interests of everyone, whether that's 10yr old Timmy playing with his mates on the floor or someone at a top table competition with 500 attendees.