Strange, dynamic campaigns are what about 75% of the market constantly harps on about in every combat sim forum.
Incorrect. It's not "75% of the market". It's "a large portion of people on internet forums", which might look impressive but is still only a fraction of a percent of the "market". Most people that purchase combat simulators never post on a forum.
It's unusual that so many developers should be so blind to the elephant in the room in their dash for MMORPG dollars.
For the reasons mentioned above, it's not that developers are blind, nor making a dash for MMORPG dollars. (That's random? Where did that come from?)
They're basically storming past an unlocked bank with the safe open to steal some kids lunch money.
An unlocked bank with an open safe makes you no good if it costs more to get close to it than there is in that safe. Let's illustrate this in an easy fashion:
1) Companies in the recent decade that have made good(ish) DC's: Microprose and Razorworks.
2) Companies in the recent decade that have made a good(ish) DC and were rewarded with enough sales to stay in business: none.
There's a lot more to market analysis than looking at what a vocal minority is saying on the interwebs.

No matter how cool a feature is, said feature has to pay for itself. Even if and when it might mean additional sales, perhaps even substantially increased sales, you still need to consider the fact that development time is a lot of money paid up front, and the additional revenue must offset both the costs in time and development money but also capital costs, cover delays in getting revenue on working capital etcetera etcetera. Simply saying "we'll make the most awesome thing ever" is a sure way to end up never releasing a product at all because you run out of money - or, if you release, not making enough to pay your debts.