Your point about "doing the right thing" is a complete logical fallacy. Are you implying that group A is somehow more deserving that group B?
Don't forget - the "tech giants" you refer to are comprised of people, most of whom have jobs and families
This isn't about whims of tech giants - more about whims of the market.
If the pitchfork-waving masses on HN screaming about Revolv had all actually, well, bought a Revolv, I suspect the company wouldn't have gone bust. The fact of the matter is - the market (or we) spoke - we didn't like Revolv, and that was the reason they failed in the marketplace.
I don't think Nest made any secret of it - as soon as they bought out Revolv, they announced it quite publicly on their blog - we are stopping all sales of this product, immediately - but we will continue to support it for some time.
This was no deep conspiracy - it was, well, the product's a wash, we're buying out the company, and keeping the team.
Think about it - they probably still had stock of the product lying around at the time - they would rather just destroy those than sell them - what does that tell you about the product?
http://www.theverge.com/2014/10/24/7061557/nest-acquires-rev.... http://www.cepro.com/article/theories_on_home_automation_hub....
There were heaps of pundits at the time who speculated on why Revolv failed.
I think that's a far more worthy topic of discussion (i.e lessons learned on why it didn't gain traction), than going on about why we're not supporting a failed product from 2 years ago.