So you get the place to the point where it opens, and then you do a trickle of night work over the coming months as replacement parts come in and you can finally get everything perfect.
Hell, this happened to my parents' house remodel recently. They scratched a custom-order door in a way that wasn't repairable. Rather than leaving my parents without a door for a month, they left it as-is and then came back a month later with a new door (once it was ready) and installed it.
The software analogy doesn't hold, because security issues are often a consequence of buggy software, whereas shoddy finishes don't have much casual connection to the interior structure.
Also, software that "runs smoothly and presents a good used experience" can be just as prone to security problems, again because there's no necessary casual connection between the two.
You could argue that if the same team is responsible for everything, that the user experience, or finish, may be indicative of the internals - but it's common in both software and construction for different teams and even different companies to be responsible, and there can also be reasons to prioritize the areas differently and devote more attention and resources to one than the other.