So I cannot add new S2 device without wrecking my old devices. 6 Oct 2021

Sonos is counting on new customers to more than make up for the loss of that market. As another early adopter, I don’t like the approach, but I have found ways to expand my set up sans Sonos.

In case you aren’t aware, you should be able to get 30% discount for each legacy device you own  to purchase new devices.  This doesn’t brick your existing speakers, so you would be free to use them as a separate S1 system, give them away, recycle, or sell them as you wish.   And of course there are reasons why the more modern and capable speakers in an S2 system can’t play with legacy products...hardware limitations and system features.  Whether or not that upsets a customer is really going to depend on the needs of the specific customer.

If the idea of upgrading your system to S2, which is understandable due to cost, or running a split S1/S2 setup doesn’t work for you, you may want to look at the used market.

Sonos has always needed new customers in order to maintain and grow their business, just like just about any other business.  The fact that some customers are just now seeming to notice and complain about the split, even though it happened over a year ago shows that they can’t just rely on existing customers to keep revenue coming in.  As well, they aren’t going to appeal to customers, new and old, if they can’t match or better the features in competing systems because their products/systems are limited by the hardware on decades old products.

Fair enough, for all of the above - although Sonos is, I am sure, also getting business from early adopters that remain fans and there is no knowing how much of a market is that lot - and I can completely understand and therefore accept if my older units cannot keep up with the new features that only enhanced hardware can provide. My issue was/is with not being able to keep older units, with no additional features available, on the same system as new units that get added in time, in the one home. 

But, there are ways to move past this and add other makes to the same one system, and have all playing as one installation - one just has to get past griping about Sonos and look for options to move on with that allow this; options that do not involve either dumping old hardware in working condition, or accepting the clunky split system approach.

You do understand that Sonos would have to spend extra time and money to develop, test, and maintain new products working on S1?  That new products on an old system would have a limited set of features that would probably confuse and upset many customers?  That the S1 system will only get smaller in time?  Sure, customers will always opt for more flexibility, but that does not mean that a business can always afford to offer exactly what a customer wants.

As far as the size of the market for early adopters, Sonos does have the 30% discounts available to help bring them to S2.  As well, many of those early adopters may only have 1 or 2 legacy devices in their systems, as was the case for me, so not as big of an issue.  Others may have already replaced their old products with new along the way, and again, not as big of an impact.  Regardless, Sonos knows the size of their early adopter market and made the decision they thought was best.  Indeed, their sales performance since they made the switch does tend to indicate they made the right choice.

That’s not to say that some customers would have preferred Sonos taken a different approach, regardless of whether it was the right move for Sonos, and are understandably frustrated.

It’s been explained 1000 times - S1 devices cannot work with S2 devices if S1 doesn’t have the S2 device defined.  Since S2 only devices came out after S1 was split, and S1 cannot fit any more device definitions due to hardware limitations, S1 cannot work with S2 only devices.  This fact also explains why S1 can work with S2 devices which were defined before the split.  It’s Engineering 101.

Some are frustrated perhaps; speaking for myself, it turned out to be the classic situation of a window closing to allow a bigger and better one to open.

To enable me to move to all S2 I would need to replace a minimum of four S1 devices.

The cost including 30% discount is $1,677AUD.
In doing this two expensive CONTROLS would be rendered useless making the system less convenient to use. Note that 30% discount is one for one so I would get NO recompense for the CONTROLS because they do not have an S2 replacement and I do not need more speakers or components.
Also my android phone does not support S2 software so another thing that would not work.

What am I supposed to do with the old SONOS gear?
I have no use for it if it will not work with the S2 system. I have no use for a separate S1 system.
Used market is flooded with old SONOS gear already so doubt it is even worth the bother attempting to sell it. So it would become junk or worse, landfill.

I don’t see why the new products could not have been made backward compatible.
I DO NOT NEED whatever the extra features/functions are of S2.
My S1 does what I need and does it well.

What is to stop SONOS doing this again with an S3 version forcing yet another cycle of upgrading costing us yet again.
 

If you write about what you are seeking to do by an expansion of your present S1 system, you may get some useful ideas that do not involve replacing existing units.

In some respects it is ‘kicking the can down the road’ a bit, but you could replace the PLAY:5 with a used unit. 

I re-read the opening post from which I see that the quoted arises. There are other solutions if one of the many units the OP has today is an independent zone - in which case that unit may be brought in to replace the play 5, while a new Sonos unit can be put to serve the said independent zone, running on S2. Or, especially if only streaming service are a source, a non Sonos unit can also serve just as well there. And if either unit is also capable of voice control, there isn't even a need to access the S2 controller except for the first set up if the chosen replacement is from Sonos.