GW's entire business strategy has always revolved around constantly getting new kids hooked on the game and milking their parents for every penny for 3 years. Their stores are set up to do that, and their rules for playing in store just reinforce it.
They don't and have never cared about the long term player, you aren't a big enough slice of their revenue for them to bother with. All their metrics point to the first three years in the hobby being the biggest spend, ~85%+, with a sharp drop-off as the kids discover girls and alcohol (yes, really!).
Maybe one customer in 500 actually stays with the hobby, and about 1 in 10 come back after a period away entirely (usually just in time to introduce their child to the money-sink).
No doubt you have the urge to spout some nonsense about how you can/do spend more on the hobby now you're an adult. How your free cash is more valuable etc. etc.
Rubbish!
If that was your urge, what you're failing to understand is GW simply don't want you in their stores. Young kids playing games in full view of other young kids is how GW advertise, word-of-mouth in schools and playgrounds, between parents at school drop-off and school clubs is their free marketing. A sweaty, overweight man-child with 10-years-out-of-date models in a store surrounded by children (and yes, there is a trend in the "type" of people who stay in the hobby) is exactly what GW don't want parents to see.
Again, you'll no doubt insist that you are personally responsible for introducing hundreds, nay thousands of gamers to the hobby through your vast social network and casual aquaintances (who are all now spending every penny they earn on GW products).
Again, bullshit!
The one in 10,000 who actually continues to successfully advertise for GW after becoming an adult (without being paid? why?) still isn't worth their time compared with even a single new 12-year-old.
So, suck it up, you aren't their demo any more. Either learn to enjoy what you have or move on to a product from a company that targets your age group and interests instead.
(far too many years burning myself out for a salary that largely went on more models)