There are tens of thousands of satisfied professional environment users who are using SoftRAID for production. SoftRAID is free during warranty periods. all upgrades, and full support, including telephone support.
The fact you do not get "free stuff" after warranty expires is not "misleading advertising". Who pays for the cost of developing those upgrades at that point?
Its a matter of who you think should pay those costs and in what way.
if you want to argue we should charge $100 or $200 more per enclosure and offer free support for longer, you can. You do not have to meet payroll. We made decisions to keep the company alive and thriving long term. It is more important to ask, "Will OWC be here to support me and my company's requirements in 5-10 years?" That is my perspective, as an employee, customer, and support person.

And the way we ultimately implemented support plans is clear and easy to understand. Have an active support plan and need support? You can call in, email, or chat and get quality technical support. You get free upgrades for the new MacOS, and other SoftRAID upgrades. Expired support plan? No additional upgrades. Your volumes always mount, your data is always available. Its understandable. It took a couple years to implement this model, but it works and it is easy to explain.

You are correct the site does not state explicitly all SoftRAID updates during the warranty period are no charge.

The web site/sales pages are undergoing a upgrade, and the SoftRAID portion will be updated. New language will reflect the pricing model, I am pretty sure. 

The software/hardware integrated products space is moving towards this model however. Look at internet routers, the good routers most all want annual fees.

Here is an example:
https://www.amazon.com/NETGEAR-Nighthawk-Tri-Band-Whole-System/dp/B08V2ZGBNK

Nowhere does it say that Netgear Armor is a $99 year expense. Maybe it should.

When you compare OWC integrated solutions with hardware RAID, even after 5 years, it is less expensive to purchase the Thunderbay than hardware RAID solutions, which often are not repairable after 5 years. Our thunderbay (thunderbolt 1) solutions from 2014, are still fully supported by SoftRAID.

Support and upgrade revenue goes to support SoftRAID engineering and our excellent technical support. That is not cost-free.

Reminder: The forum is intended for technical support. You can address complaints to leadership@owc.com, where they will be read by upper management.

I am sorry, but this is how it is.

MacOS has major changes every OS release for the past 7 years. It takes massive engineering to keep up with the changes. We cannot tax future owners to support older ones.
with a support plan comes telephone and chat support, also.

Promise, since you named them, has no need to support MacOS in the deep integrated way we do. (And they abandoned users of their older enclosures with M1, while we still can support them) hardware RAID controllers can easily fail also, where you are stuck as you cannot put a newer controller with your older RAID.

One advantage of hardware RAID is its set it up and forget about it ability. On the other hand, you must get certified replacement drives in most cases, which cost more, the controller can fail, etc. So it is a trade. With SoftRAID if your hardware fails, just put the drives in a new enclosure. We support multiple RAID levels with the same drives as example for more flexibility.

SoftRAiD has a long term growth path, which has slowed because of the changes to MacOS each year, but we are catching up, and next year, we hope to show significant new features in return.

If you want to use your enclosure as JBOD, you can, and it will be reliable.

You received a 3 year warranty with your enclosure I suspect. You are eligible for free support and all upgrades during the warranty period. After that, to keep getting upgrades and support, we ask you to renew your support plan.

No, you are not required to renew support, but to take advantage of SoftRAID with future MacOS upgrades, you do need to.

if you do not upgrade MacOS this fall, you can keep using SoftRAID with your enclosure and computer. You can keep using your enclosure without SoftRAID, (use Disk Utility or Apple's RAID), also.

But to keep receiving support and upgrades, you must have a SoftRAID support plan in place.

The last version will be the last available on your support plan's expiration. Yes, you will be able to download that version again. I am not sure of the mechanism yet.