The best engineers are obsessive, but that doesn't mean they suffer from OCD, which as you said is an anxiety disorder. It is one thing to obsess about details of a circuit, to make sure every parameter variation has been verified and simulated or tested and that no failure mechanism has been overlooked -- that is called being thorough. It is quite another thing to repeat the same behaviors over and over, especially when the purpose of repeating them is simply to avoid or to relieve unfounded anxiety.
Another acronym that I think we overuse is ADD. In my observation, the best engineers are able to hyper-focus when they need to -- dive into a task and get completely immersed in it, shutting out all other distractions until the task is completed. Hyper focus (too much attention) is often considered to be a symptom of ADD, even though we tend to think of ADD as an inability to focus. But it's only a "disorder" when it becomes a problem, or when it exceeds some threshold that we collectively think of as normal behavior.
It's ironic that those with an inability to focus for long periods of time -- those with more typical ADD "distraction" tendencies, are often seen as being successful multi-taskers -- people who seem to be able to make regular incremental progress on multiple tasks, even if some of those tasks fall behind schedule and some never get completed at all.
The ideal engineer has no "disorder" at all, but has a tendency to obsess over details to the point of being thorough, and has an ability to tune out distractions and focus attention for a prolonged period of time to accomplish a difficult task.
I don't believe that the passion to make things work can be compared to OCD. Creative people are always driven to perfection when pursuing ideas never before made real.
Engineers do not suffer from a disorder.
Others suffer from a lack of vision and dedication.
Just my opinion.
I think probably we all have little bits of obsessive+compulsive behaviour. Habitual behaviours are similar. We 'have' to do them.
OCD is where that behaviour becomes excessive. It's fine to double-check before you leave the house that the doors and windows are locked. If you have to do it more times, it's probably OCD. It's definitely OCD if you always have to do it, for example, an exact multiple of four times.
As DCH said, it's a survival skill. I remember an example from some years ago .. a brand-new right out of the packaging toilet brush dipped into a glass of water and someone then invited to drink the water. They wouldn't. Probably neither would I. It's illogical, obsessive, compulsive ... and normal.
I think a good engineer is obsessive about detail in the same way that a good surgeon is. And, in the same fashion, is capable of focusing completely on a single task to the exclusion of all external distraction. These are very valuable qualities in people whose occupations require them to get things right first time.
I see a difference between OCD and a good Engineer ( or anybody being the best at anything, for that matter). Professionals that excel at what they do have a goal in mind, they know what details make a difference in their performance/product, vs OCD people just obsess but I wonder if they have a plan in mind or they chose the detail/behavior to obsess with.
A good Engineer will know when and when not to zoom in a particular issue. Having Priorities make the difference, in my opinion.