You are allowed to count spinoffs, it is how pokemon gets to be called a series after all.
Erm...surely we agree that pokémon has more than one full game, right?
But in all honesty...how many dragon's dogma spinoffs are there? Following your post, I googled up a 'dragon's dogma quest' game...and that's it. Granted, it's more than nothing, but still pretty meager.
The problem isn't so much F2P as it is F2P that gives you the option of spending $1 on a sword, or doing 16 quests, 8 dungeons, 4 raids, and you have to fuck the queen of the universe to acquire the same sword with "free" options, which is how most of these F2P+micro-transactions games are. Of course you have a choice between spending that $1 and spending some amount of time to get the same thing, but it's never in a proportional sense that's actually worth the effort which is the problem.
This is the symptom, but not the real problem. I'm not too familiar with DD, but I wager to guess the whole reason you want to play that game is to do quests, raid dungeons and fuck the queen of the universe. Unfortunately, for F2P games, that focus is different. The actual customers of these games* are the ones NOT playing the game. And that more often than not results in a changed market. Rather than focusing on having the best quests, mechanics, required skills and so forth, the focus becomes on loot drops, rewards and social comparisons (not by coincidence things that encourage you to spend actual money to keep up with other players).
*to a developer (or anyone else not working for charity), the customers are always the ones who pay. They don't make the game like pirates want it to be, and they have no reason to listen to players who are stubborn to not paying a dime on a F2P game.