If there is some migration to another category going on, I don't understand why it would take this long to convert?
Taxonomy discussions within the directory can take months...or even years.
Actually I don't see that many listings in this category. There are many more in other related categories.
That is likely why the top category is closed to suggestions. If and when someone gets around to listing your site (assuming it's listable), they will list it in the top category if they feel it belongs there.
a. I have no idea if my site was every reviewed.
If your site is listable (i.e. it doesn't fall into any of the categories of sites that we don't list), then the fact that it isn't listed can be taken as a sign that it hasn't been reviewed. If the site isn't listable, then its review status is irrelevant.
b. I cannot know who reviewed it, to see if there was a conflict.
See my comment above. The usual answer to the question "Why isn't my site listed yet?" is "No one has gotten around to reviewing it." Conflict of interest and abuse is uncommon.
c. I was given no reason why my site may have been rejected.
Per my answer to point (a), if your site is listable, then there is no reason to think that it was rejected at all.
d. Maybe my site was banned. No way of knowing.
Sites are not banned lightly. If your site was banned, you'd likely have an idea that you'd done something wrong. Again, in all likelyhood, the site just hasn't been reviewed by anyone.
Considering the open and transparent nature of the Internet today, I would have to say this level of contempt for the companies that Open Directory relies on for content is unheard of.
It's not contempt. We are humans and each of us has a finite amount of time and energy to devote to the ODP. If no one has decided that this category--and more specifically the unreviewed pool in this category--is where they want to spend that time and energy, then it can take a long time for a suggested site to be reviewed. It's not contempt, it's just the way things work. This particular category receives a massive amount of suggestions and the number of people who will have the urge to slog through those is likely fairly small, which furthers extends the time it can take for a suggested site to be reviewed there. For example, the chances of me ever decided that I have to edit there are slim to none because the topic just doesn't interest me. So none of the 20+ hours I will spend on the ODP this week will likely be there.
If your company has an actual physical presence somewhere (as opposed to being strictly online), you might consider also suggesting it to the locality category where the office is physically located. Regional categories frequently have shorter review times.