First of all, nobody is voting because you didn't make a poll (EDIT: oh I see you did now). You won't get as many responses if you ask a general question and require people to write answers (unless you say something really inflammatory like "Why does this game keep getting worse?").
And I think you're oversimplifying the issue. Yes, the "easy" solution would be to just turn the spawners up to 11, be tripping over mobs everywhere you walk and have fields of 40 wolves to kill.
But then you aren't making MO2, you're making every other MMO. The primary goal in MO2 is to create an immersive fantasy environment based on realism where possible. Wolves travel in small packs, not in packs of 40. You don't step over wolves every few steps you take even in the wild.
What I think you are asking for is you want more interesting content as you traverse the world. To make that feel "good" and immersive, they need a lot of things. They need more points of interest, they need more variety in animals/monsters, they need more dungeons, they need more variety and interesting bosses to face. Good thing everything I just said is represented in basically every patch until release in the current Roadmap:
Sign up for the Mortal Online 2 Closed Beta
They know lack of PvE content is one of their primary issues. I've been following the beta for over a year now, and they have prioritized jamming in PvE content and variety now more than ever before.
I suspect they have areas of the map earmarked already for all kinds of various content, it's just a matter of building it, and likely they have planned what they intend to have in and the PvE density they want to have at release.
Putting in huge packs of 40 wolves does nothing but make them have to remove that later when they put in actual content and simultaneously just creates a "field of grinding" experience you get in most MMOs which is not what they're going for.
In summary: They know they need more stuff, they are working on it heavily as evidenced by the roadmap, wait until release to render final judgment on "they need more stuff".