Universal is not the yardstick by which Walt Disney World development should be judged. I know many posters, and not just yourself, like to compare the two but in many ways it just isn't a valid comparison. Universal doesn't have four parks which have been neglected and allowed to grow stale over many years, in some cases actually longer than the Universal parks have even existed. Universal doesn't have as many old attractions begging for an update, nor anywhere near the extent of infrastructure which Disney must maintain. They don't have so many resort rooms to fill either, which is a critical difference.
If Disney is building like Universal - they aren't doing nearly enough. But they aren't even doing that.
Disney hasn't seen an appropriate and necessary level of investment in the parks and resort for many years. You are absolutely correct that there hasn't been this much construction in the last ten years - but that is exactly the problem we are trying to explain. Major work in the parks and on infrastructure has been put off for far too long. Indeed, several years have passed without a major new attraction opening anywhere on property at all. Both resort transportation and the parks themselves lack needed capacity for current crowd levels, and while numbers continue to grow that is primarily at just the Magic Kingdom, which exacerbates the capacity issue. Numbers at the other parks remain very roughly in the same ballpark as they were years ago.
Even if silly plastic bracelets really had been the greatest thing since sliced bread, had been on-time and on-budget, and hadn't experienced such a bumpy rollout it still wouldn't take the place of actually constructing and building new things - attractions and infrastructure. A tracking device which attempts to better manage your existing assets can only do so much. At the end of the day what people come for are the attractions and other resort experiences - and over the next three years, we have one or two confirmed additions.