Looks like it is a difference in culture that I am used to and the one that you are used to.
At my workplace, it is perfectly acceptable for someone to suggest a complete change to our CI/CD process. In fact, we have changed our complete CI/CD process twice (SVN/build scripts -> Mercurial/Jenkins -> Git/Travis-CI) already with minimal loss in productivity because someone questioned the existing CI/CD process and suggested a well thought plan to switch to a new one.
But I get your point that sometimes it may not be feasible to carry our such a drastic change in process, infrastructure, etc. But suggesting such a change is going to be acceptable and we refusing to accept such a suggestion is also going to be perfectly acceptable and both this person and us working in harmony even after this disagreement is also going to be acceptable.