the second miners increase the block reward or change any fundamentals of why we love Bitcoin we can quickly discard them
That is the point: with a soft-fork type of change, old clients would not even be aware that the change was
deployed and activated, unless they read about it somewhere. How many bitcoin users follow the forums
(and know about the reward schedule)?
No, its akin to a seller telling a merchant that they have been paid/ them checking their bank or paypal account and not seeing the funds, and the seller socially engineering the merchant to go to a different site and login to a fake bank. Of Course some idiots will fall for this , but most will be alarmed and do a speck of research before accepting the fraudulent software.
Switching the PoW algorithm will not jam the miners' equipment. They would
continue mining as always, and every user or business will continue to
use their blockchain by default, "secured by a network with 1.5 PH/s
of mining power".
What "switch the algo" actually means means is that the Faithful will create
a new altcoin, say "TruCoin", that starts off with the current state of the bitcoin
blockchain, but has only a modest amount of CPU/GPU mining; and will ask
everybody to ditch their bitcoins and use only TruCoin.
But, to do that, users would have to download a new version of the software.
You are quite correct that the ASIC mining cartel will be left with a pathetic 1.5 PH/s of hash power(Did you forget what year it was?) because their new alt they created with higher inflation will be practically worthless. The other alt, you call "trucoin" would certainly also take a massive hit, but could recover in time.
How many do you think will bother? My guess is fewer than 5000 bitcoiners...
21 million is so intrinsic to the identity and contract of bitcoin most would move over, but for the sake of argument lets assume only 100 people move over... Do you really think we care? You are making an assumption that we are only greedy speculative traders who have no principles. I will never accept or use a bitcoin alt that changed the inflation rate.