Ok, funny image, but think about it. The terms of MEC's lease at the new property were probably set in advance. Meaning they agreed ahead of time what MEC would pay and for how long.
Even though MEC has an ownership stake in the site, there will still be a lease between the landholder group and the tenant.
In build-to-suit situations like this, the developer is obligated to deliver a certain building (size, specification, quality) etc. as detailed in the agreement, and in return the tenant will take occupancy and pay rent.
So if this was a typical build-to-suit structure, the developer now is incentivized to spend as little as possible to satisfy the building requirement as minimally as possible. Sometimes the architect is a kind of soft check against bad build quality and design, but in this case the architect was the same entity motivated to build as cheaply as possible -- if this job is structured as it typically would be. And on top of that MEC, the tenant, is the same entity that has a piece of the land ownership (and possibly a contributor to the capital costs of the building) and is also likewise motivated to spend as little as possible.
So there is an alignment of interests created by duplication of project roles, all pointing towards the job being done as cheaply as possible. Which is exactly what happened. I don't think this is a conspiratorial hypothesis although I welcome anyone to point out gaps in my theory or alternate possibilities.
What we know for sure is that this is a shit building. We also know the architect is one of the development equity partners, as is the tenant. Occam's razor, unless I am missing something, suggests that the deal was set up (inadvertently or not) to motivate the developer to build as cheaply as possible.