Lessons not learned....
1. VR hardware is expensive - you better have something compelling for people to purchase it at scale or you lose money fast due to development and production costs.
2. Get a grip on the engineers! They will have produced version 21 of the hardware before you have even recouped the design costs of version 20 - the more you sell the more money you lose.
3. Trad flatscreen experience coders/authors are usually poor at 3D immersive environments - they don't get that if you were looking the wrong way it didn't happen.
4. Complete lack of standards meaning experience authoring costs are high across platforms.
5. Headsets that look like a diving mask, glasses that make you look like Joe 90 or the Borg.
6. Lack of compelling experiences beyond games and gimmicks - your audience is also not in the high earning category.
7. Major - Legal - Little Jimmy spends all his time in VR worlds, now he needs glasses (he would have done anyway) - class action lawsuits!
8. Completeness of vision - you really need to have VR, AR, telepresence, and teledildonics.
9. Privacy - what happens in VR worlds is subject to what legislation? AR and video recording... remember Glassholes?
AR has a much more compelling business case than VR if you can avoid creepy glasses and implement Privacy by Design: This is Fred, at the last meeting he spoke about carrots and you agreed to speak to the rabbits. This is Jane, you met at the conference last year, she drinks gin and tonics and has a pony. This is your son David, don't worry you have had a few memory problems and are in hospital, everything is OK.
(For context I used to be product manager for immersive virtual reality systems at IBM (Project Elysium in conjunction with the UK company Virtuality)... in 1995. What goes around comes around, sometimes people have not learned the lessons).