The list was based on iFixit's findings from its teardown work. Two of the biggest reasons for low repairability scores were excessive adhesive and a high probability of breakage during disassembly. The majority of Apple's iPad family were guilty of one or both of those symptoms.
The lone Apple tablet with a good repairability rating was the original iPad with a 6/10, notching in below the Nexus 7 on the list. The only negative for the original was that the battery was difficult to remove or replace.
The list doesn't include every tablet released, but it does include some of the more popular ones like the various Kindle Fire models and the Samsung Galaxy Tab. The top tablet on the list was the Dell XPS 10 with a 9/10, while the Microsoft Surface Pro scored worst with a 1/10.
In the past other Apple products, like the 15-inch Retina MacBook Pro, which received a 1/10, have also received criticism for being difficult to repair from the iFixit team.