A bit worse than that; from a friend who looked at it:

They didn't do the basic end to end work, so creating a client to display a Xanadu document was almost impossibly onerous. You had to grok and use around 6 different things, and, well, however nice the backend might be, it just wasn't practical.

Also an example of the perils of stealth mode, I found the above believable simply because they'd been in stealth mode for decades.