Well if the hardware is ready, then why wait? I know, it took a LONG time to iron out the Pimax 4k issue's but still, I was happy to receive mine, even though it was VERY far from perfect at the beginning (remember when we couldnt even run 1440p but max 1080p?). Even though customers bought the 4k online (not even via kickstarter), I think pretty much everybody accepted that the development was ongoing and not even near perfect. Heck, it's safe to say that the first versions that were sold were not even beta, but rather alpha stage.
I'd rather receive my 8k now, buggy and not perfect than wait weeks (months?) before all software issue's are ironed out. Or at least give backers that option. If others prefer to wait, fine. But i'd like to receive mine when the hardware is ready. Which is now, according to Pimax themselves. Remember, obviously the testers have given their OK with the hardware otherwise Pimax wouldn't have said they were now in the hardware mass production stage. Also remember that Sweviver has now probably used the HMD over 100 hours, which he wouldn't have if there were serious issue's like IPD problems, he said so himself and that makes a lot of sense.
So ... if backers are ok with the fact that the HMD will be far from perfect, but at least won't receive any more hardware updates, then why not ship out to those backers already? They did so with the 4k and now we're even kickstarter, not even online shops