There are a lot of responses here that say "All tablets are like that".
First, Many of those tablets cost $200 (Nexus). It is a lot more acceptable to have a sealed $200 device than a sealed $1000 device, regardless of form factor.
Second, Almost no other computing device is sealed to this extent with an inch wide strip of tar like adhesive that needs a heat-gun to pry apart (who knows how well it will go back together). I take nearly everything apart, but I would mess with this kind of extreme adhesive job, especially on a $1000 device.
Third. It isn't even about repairs. If this was pure reliable solid state, it wouldn't be a big deal, those parts could run for decades. But this has two fans, meaning they will accumulate dust/have bearing failures, and in few years need replacing/cleaning, it has batteries with short finite life that will fail in few years, the SSD is small size and has an OS with propensity to write a lot to it (swap files) etc, and has a significant chance of failure. These should be considered serviceable components, because chances are significant that one or more of them will need service in a few years. Having them sealed, non-serviceable in $1000 device is unacceptable (IMO).