I want to know, why some developers who are part of company "Blockstream" which will benefit from addition of Segwit/Lightening network to bitcoin,
Blockstream does not benefit from segwit or lightning. This is an oft-repeated claim that is untrue; Blockstream's work is primarily focused on sidechains, not segwit or lightning. Additionally Segwit and lightning benefits nearly everyone who uses Bitcoin, not just one company.
I have not checked in depth and will need to do more research regarding their field of work but a quote from their website:
Lightning Networks
Blockstream is collaborating with industry leaders to create a Bitcoin micropayment system that supports high volumes of tiny payments using proportional transaction fees and that operates lightning fast. We are now developing Bitcoin Lightning prototypes and creating consensus on interoperability.
Also the statement "Additionally Segwit and lightning benefits nearly everyone who uses Bitcoin, not just one company." should not be made, it is your opinion and again you assume it is correct, when we are trying to judge its correctness. If it was as good as you say it is, then you think that a lot of other people are stupid that they cannot see what you see.
I have no issue if some developers support segwit/lightning network, but I think they are abusing their position/power to force it to everyone involved with bitcoin.
The Core developers have no way to force everyone to use segwit or lightning. If they were able to, then segwit would have deployed months ago. Furthermore, the Core devs are not working on lightning, other people are doing that, and not under any sort of special instruction from the Core devs to do so.
So you are saying there is no overlap between Core developers and
https://blockstream.com/team/Just because a person of a company is not working on a project of a company it does not mean he does not want it to be successful. An employee is expected to support the projects of his organisation.
I think the ethical thing would be to step down as core bitcoin developers , giving up git commit access to main bitcoin repository and similar powers.
Only ONE developer who has commit access to the Bitcoin Core repo works for Blockstream. And he is not in charge of Core nor is he a maintainer of the repo.
It is related more to having the power to directly influence those who will ultimately make the decision. If they are not part of blockstream then they have equal right as all other developers but when you are to judge on a product your company is working on, you should not have the power of making/influencing the decision.