I think a lot of the problem is in presentation.
The quote in the OP isn't saying, "Hey, guys, it's a lot of fun in Fronen! You should come, too!"
It's saying, "If you want to create an adventurer, create one in Fronen. If you want to create a noble, create one somewhere else, then emigrate it to Fronen. We just started a war." (The implication being, "So we need more people to help fight it.")
Furthermore, it's an IG OOC message. If it were being sent via some OOG channel, I wouldn't think much of it, but this is more like blatant advertisement being pushed in your face.
Rather than a friend simply saying, "Hey, it's fun over here! You should come be here too!", I would characterize it more as being like a billboard being thrust in your face, or a used-car-salesman-type appearing in front of you and shouting, "Hey everybody! Fronen's the place to be! Everyone should be in Fronen! Fronen: The Fun Place™!"
It smacks of advertisement and artificiality, especially because it's being sent to this broad group of (I believe) adventurers.
I disagree with you on quite a bit of that actually.
Adventurer guilds can make being an adventurer much better when they are actually used. If someone were to ask me where to make an adventurer, I would recommend Fissoa, Dwilight. They have the Fissoa Verminators or something like that its called. I am actually not in the guild to help the guild but for some other, unrelated reasons. The letters I receive have shown me it seems that the guild makes being an advy quite a bit better thus it would/could make a difference in choosing where to be an advy.
While you see them mentioning war as them saying they need nobles, I see it very differently. BM can be very hard to have fun without war as a simple knight, which is something I think needs to change, thus if they is war there is a much larger chance of fun as a simple or new knight.
Overall what I am trying to say is that they are giving reasons why Fronen is fun and not, strangely as you would prefer, just saying the realm is fun which seems more like boring advertisement of Fronen for gain for them then actually trying to help people to find a good realm.
Due to the advy game sometimes having issues with being fun I wouldn't see it as terrible to let some nearby advys (actually probably all they advy's of his realm) that Fronen is a fun a place to play. I can't say I love the idea of the OOC IG recommendations to a group of people (to one person can be a bit different) but I don't think this was so terrible it deserves to be banned in general.
To OOG recruiting, I see nothing wrong with it. I would hope people are recruiting people to realm's they will have fun in meaning I don't care if you are recruiting for your realm but I hope if you are recruiting for your realm, its actually a fun place to be or someone there is working on reviving it. While most recruit for their realms, not everyone does. A couple weeks ago someone was looking for a good realm to join and I convinced them Silnaria would be great for them. Lastly, OOG recruiting on a non-BM thing it is always good if you are recruiting to an actually fun realm while recruiting to a boring realm does hurt BM because they see BM as not fun, thus making them more likely to quit and they chance they discourage others from playing.
