May have something to do with an old saying; the fastest way to make a small fortune in games is to start with a large fortune. Look at what happened to ICE, TSR, and Avalon Hill when the money bags dried up.
To be successful a game publisher needs to know how to run a business, and how the games he publishes work. Board games have one dynamic, real time computer strategy games another. Then you have RPGs, with a dynamic all their own.
You play boardgames to test yourself against others. Whether it be Settlers of Cataan or Risk. You play RPGs to test yourself against a situation set up and controlled by a GM. A GM you hope is honest with you. In an RPG you are not trying to win, but to succeed in achieving a goal. Which may sound like winning, but has important differences once you think about it. As a matter of fact, events in a session may change things so dramatically that the old goal becomes at best irrelevant, or at worst the worst thing that could possibly happen.
You get right down to it, knowing how board games, card games, or miniatures games work may work against you where RPGs are concerned. For the tendency is to view RPGs as like other games, when really, they are not. RPGs, for all they have tradtional game elements in them, are on the whole a whole different kettle of fish.
If you're a small company stick with traditional games or RPGs, don't try and mix the two. If you're a big company have separate divisions for the two, and try not to mix them up. Your business will be healthier in the long run.