For me it's a cathedral's worth when the last time I saw anything close to that level of facility for DM prep in D&D was 14 years ago. I play Pathfinder lately due to group demand, and the most aggravating feature is the whole "prep a monster for two hours and it gets taken down with a save or die spell" effect. It's not just artisan created monsters either - anything above level 8 or so has spell effects worked into its CR, and when anti magic fields, dispels, and status effects start flying, I worry about math more than story or thrilling combat. A good D&D for me is one that will give the custom monster fans their fun, give me a simpler, raw numbers based alternative that will give any given party level a run for its money, but will be able to keep straight in my head instead of on paper. I've learned tricks over the years to bypass this effect, but any custom crafted tool I and others have found we need to finish a job, I want one standard in the toolkit.
