That's half true Wolfe, if the pool of players doesn't grow, sure, you need to release more and more models (see GW right now), but if you are growing, you want to grow more, and that doesn't require you to release like crazy because the new players will also buy the old stuff if your game is well balanced (and since upgrades are shared, you may just want a ship... for the cards). It requires to have a community that plays, support the game, gain trust from your players, and try to balance the game.
Once you hit the top sure, but that's when you release 2.0 and mix things up, withouth going full GW. You never go full GW (inflating point cost to sell more models, completely destroying your game in the process to also sell Big models).
Remember when GW first came out the model prices were fairly reasonable. 30 plastic guard or orks for $30, 10 plastic space marines for $10. The metals were not bad either in general you got 2 to 3 models for about $8 unless it was a character then they were about $6. Somewhere over the course of 3rd edition things seem to have gotten priced by the battlefield value over the actual costs of making the model. FFG is technically in the Rogue Trader era of X-Wing at the moment. Hopefully they look at the lessons of GW and learn from them. X-wing is not cheap to play however it is still cheaper than 40K and WFB.