Clear evidence of Blockstream controlling the Core code base to prevent block size increase can be seen here, someone offered to help increasing the blocksize, but the issue was closed immediately by sipa (Pieter Wuille, Blockstream co-founder):
https://github.com/bitcoin/bitcoin/issues/10028You can see Pieter Wuille closed the issue immediately but then try to justify it with the usual corporate double speak by claiming the issue is up to the community and out of his hand.
This is what we call 'lying'.
If we're talking about increasing block size from 4MB to 8MB, there maybe some room for debate.
But nothing can justify not going form 1MB to 2MB, there is a real backlog and the safety limit is above 4MB.
Blockstream is clearly holding the bitcoin code base hostage.
Here is another pull request for block size increase, closed immediately without any comment:
https://github.com/bitcoin/bitcoin/pull/10014In the first issue that you cited, sipa said that the core maintainers do not, and do not want to decide what the network's rules are. By this logic, they would be unable to merge any kind of forks into the Bitcoin Core code at all, including soft forks. Additionally, they seem to be threatening to HF a change in the PoW if the miners do not accept SW, which implies they are both able to change the network's rules in regards to the PoW, and are saying that SW is something that needs to be part of the network's rules.