Open Source isn't all about you, but it is a little bit about you.
i cannot say who the 'we' is, but i suspect in some circles this may hold true. i do challenge that this is a reasonably held belief because it is an expansion of the historical responsibilities generally held towards those who would wish to open up their source for others. it may even suppress how much code is openly shared (since most engineers don't enjoy being community managers)
Stallman explains: "The two terms describe almost the same category of software, but they stand for views based on fundamentally different values. Open source is a development methodology; free software is a social movement."
Apple recognizes the state of this confusion and perhaps wisely uses a different definition to avoid conflict. The Clojure maintainers do not, because they interpret Open Source by its original definition. Just because a collective group is involved does not mean its maintainers are compelled to the responsibilities conveyed by Stallman et al's extension of what open source is.
Conversely, people who started using open source after the internet exploded, and I think particularly, once being an open source maintainer was seen as an achievement and goal, the attitude changed. Individual users of the software were building things depending on the OSS and felt that their use of the OSS code implied a contract for continued development of that dependency. This feeling is made worse by fiscally gigantic corporations pushing ‘oss’ products and those corporations acting like their continuing to support their product is analogous to a solo dev putting a vim plugin on github. The reality of wide spread large ‘oss’ products and the implied (and often maliciously relied upon) personal obligations of producing OSS have led to the current state. That state being users of some OSS assuming that their usage of the software means the author owes them some obligation by virtue of their need.
This whole issue is made worse by large organizations getting social credit and positive marketing by releasing ‘oss’ products. This leads to conflation of individuals releasing code to benefit the commons vs. organizations doing so to capture markets, gain publicity, etc.
Many contribute fixes and actively improve the software, but many post entitled comments.
Except there is no implicit guarantee.
For example the Apache 2.0 license outright says it, so there is no argument about "implicit guarantees"
https://www.apache.org/licenses/LICENSE-2.0
7. Disclaimer of Warranty. Unless required by applicable law or agreed to in writing, Licensor provides the Work (and each Contributor provides its Contributions) on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are solely responsible for determining the appropriateness of using or redistributing the Work and assume any risks associated with Your exercise of permissions under this License
Asking as someone who has honestly never held such assumptions, I remember quite clearly my initial instinct towards various FOSS projects as "their castle their rules", I'm kinda puzzled why anyone would think otherwise... but this is a long time ago in internet years.