IMO, attacking all of "devops" (or "agile", or "cloud computing") at once is not productive, because it means so many things. So if you don't get specific, as others have said, it makes you seem like you just oppose new things.
For example with devops, a very rational concern is that if the infrastructure team shrinks or disappears, then there's no one on the hook for making things all work at the same time. If you leave it to the developers of each team to make their thing work, you are likely to have a continually broken development environment.
A good argument to oppose any change without a clear rationale for the change occurring is "if it ain't broke don't fix it." This, at least, leads to someone explaining why change is necessary, and then from there perhaps you can have a conversation.