Tldr: Don't accept obstructive behaviour as the norm, get to the root of it because there is probably  an important reason.

Developers are often seen as being obstructive, it's pretty much part of our stereotype. But reviewing times I know I've been obstructive, or observed a colleague being obstructive it probably points to something we shouldn't be ignoring.

There will always be developers who are obstructive by nature. There are people like this in every profession so lets skip them as the exception rather than the rule.

What makes the rest of us obstructive? I think it comes from a reluctance to do the job we are asked to do. Why are we reluctant?

• We aren't sure of the requirements
• We aren't convinced by the value of the requirements
• The requirements mean we need to bend our application in a way that it wasn't designed to
• It's new technology to us
• We aren't confident enough in our own skills
• We simply hate working with the codebase because:  it's damn ugly, it's flaky, there are no tests, we don't understand it well enough.

There are many others, the point is, the cause should be discussed. There is nothing in the list above that couldn't be resolved by more/better communication, or time, or an adjusted approach.

Developers are the closest in the team to the actual workings of the application we should shout up if something is a risk or potential risk. But equally we need an environment where we feel safe to do so.