That there catalytic corrosion thing. Rust, leaks, both oil and water ingress, noise levels ergonomics oh and security,,,,,,,,,,,, or at least the lack off it.
That's just off the top of my ed.
Not outright replacing it with an expanded discovery range in 1989? There was already the 7-seater station wagon and 3-door van. A truck cab would have been simple enough on the standard chassis, and a long wheelbase double cab pickup could have been built on the 127" chassis, both using the existing HCPU tub.
They could have included a more comprehensive tool kit ... including a selection of hammers, otherwise what else would I have had to play with over the past 40 years?