I worked as an apparel product manager, so I dictated the needs for garments to our artistic design & tech design teams. I made my decisions off of sales data (both within my brand and other brands), product reviews, and design trends. Everything costs money - down to the number of seams and the stitching techniques used to make them. If I'm going to add features that increase production costs, I need to see evidence that they correlate with high unit volume in sales data and high product reviews - even better when they get called out positively in the body of the review.
I can see how the prevalence of backcountry skiing and inbound avalanches killed off the lumbar pocket since more skiers are riding with packs.
Pretty much any style outside of core silhouettes come and go over time as trends in fashion and skiing both change. But if it makes you feel any better, there's a 25 year old park rat who's going to be totally devastated when he can't replace his camouflage anorak in 5-8 years.