user centered design - Is coffee a good excuse for a slow application start-up time?

I was dragged into a meeting with a client to consult on any usability issues as we watched a user performing day-to-day operations with a software application.

The first thing that happened was that after the client double-clicked the app's icon we waited around 8 minutes for the app to load. No one in the room cared about that but me. They argued that what they do is start the application and have coffee while it loads.

Of course the user believes that the application is fancy, heavy and complex enough to load faster (and in many ways it is), and (of course) I couldn't argue (verbally) that the loading-times could improve inside that meeting with that user, so I wrote 3 technical recommendations to work-around the slow start-up time and presented them to key stakeholders. The suggestions were disregarded on the spot, as the customer didn't care about its slow loading times, since that's their time for coffee.

I know we should watch how our users work every day, but does that include coffee (or other activities that don't impact the business process directly)? Is this a good excuse?

Edit: added an illustration :)

Answer

To me, the basic logic is this:

It's better to have a fast app than a slow app. While there are many studies that show that faster applications provide better UX, it seems pretty axiomatic to me. I mean, generally in life if we want something done, then we prefer it to be sooner than later (with the exception of various aesthetic and, um, other activities where the point is enjoying the process... I doubt that an application loading is such a process although sometimes it can be made one).

The customer doesn't object to the app being faster, he just doesn't care. That's a big difference. If you make it faster, he won't come to you asking to slow it down because now he doesn't have time for coffee.

So, this is something that you generally ought to do, but you don't really need to. If it were free and you could do it with a click of a button, then I think the answer would be clear - you ought to do it. But it's not free, so it comes down to cost-efficiency. If you can invest your resources in something that the user does want, do that (provided it's the only user of the app etc. etc., as @yisela says). But if you have the resources available for this at a low cost, do something that would make the app objectively better - speed it up.

*Sometimes making specific processes slower can achieve specific UX goals. There was a famous case study where some process, probably saving or performing a calculation, was made instantaneous for a new release of a product, and users, who were accustomed that it takes time, weren't sure whether the process ever took place in the new version. This created a lot of confusion and they pressed the button over and over just to make sure it worked. So the developers pretended to slow it down by providing a quick loader or a progress bar or something, which helped put the users at ease. I can't find the link right now. But this is not the case here.