I say it's meaningless because it doesn't mean anything. It's just a number.
Against any player who plays in a tournament with you, you get either 1 win, 1 loss, or 1 tie against that player. It didn't matter if you played them or not. It didn't matter how many times you played them and what your record was. It also meant that you received more wins by playing in a larger tournament.
This was heavily exploited in 2015 when SuperLeague participants were being awarded hundreds of wins every month against players who were not actively participating in the league. The results were being recorded such that Joe NewYork had played against 200 unique players a month as if he had played 200 different chess matches against them and had won all of them. Even a player who finished in 10th place would have had a 95% win rate at which point Glicko gets extremely confident that you need to be placed a standard deviation or two higher than average players if beating them is so trivial that you can do it 95% of the time.
In addition, you should be able to use rating to calculate the win probability in a head to head match. Using IFPA rating, you cannot do this, because the rating takes into account 0 actual head-to-head matches until challenge matches are factored in.
The "fix" for this was that you only get wins, losses, and ties against up to 64 players in every tournament.