Hardware failures are common enough, sadly, across the industry as is standard industry support of warranty. What you describe is the norm, not the exception. Warranties typically apply to the original date of purchase and, in my experience, never extended beyond the date of replacement hardware.
Apple is actually much worse, selling extended Apple Care at a premium and then charging a deductible should you actually need to use the Apple Care extended warranty. This is just an example but it makes the point that nothing you have noted is atypical of the industry, in fact, a 100% replacement without additional charges, within a warranty period is a pretty good deal, especially if the replacement hardware is "new" and not "refurbished".
Conflating a simple warranty issue with the successes or failures of the Kickstarter campaign is just piling on information that though perhaps interesting, isn't particularly relevant.
What is curious is your description of events, after a firmware upgrade the A+ lost connections with all sensors. That doesn't sound like a hardware failure necessarily. Did you ship that original unit back? If not, there is a perfectly good touchscreen you can scavenge.
The second unit having a hardware failure, the touchscreen, is unfortunate. Any chance you have brown outs in your area? Was the A+ surge protected and hooked to a battery backup? Was the touchscreen on all the time displaying Weather or Time? You mention carrying many electronic devices without issue, was the A+ a mobile unit for you? If so, some basic soldered connections could be investigated.
Hardware failures suck, that's all there is to it. And any company can't afford to keep replacing units for folks, especially folks that experience multiple failures as generally that is a red flag. No offense intended, just how it is.
The Kickstarter funds reference may have been an attempt to describe some of the issues delaying software development. No one has been happy about that. R83 is good stuff so far but of course we all want more.
FWIW, replacing a touchscreen isn't a big deal. People do it all the time with RaspPi projects. Trick is finding the right one. Another option is to sell your device(s) "As-is" on the secondary market.
Good luck getting the attention of a higher up looking to work a 3rd piece of hardware in exchange for your original investment.