> Its very easy to build a highly customized and resilient system using cloud offering combined with these open source systems.
For you, maybe.
Odds are for every person with the knowhow to do this, there are 100+ who don't even know what "open source" is, let alone have the skills and understanding to even attempt what you describe.
Even among those who know what it is and might consider doing it, some portion rather spend their time selling their products (aka making money) rather than doing a bunch of things that might get them ready to make money at some point in the future.
For you, maybe.
Odds are for every person with the knowhow to do this, there are 100+ who don't even know what "open source" is, let alone have the skills and understanding to even attempt what you describe.
Even among those who know what it is and might consider doing it, some portion rather spend their time selling their products (aka making money) rather than doing a bunch of things that might get them ready to make money at some point in the future.