Perhaps that's the way some guilds work. I would surmise that there could be various reasons for the level requirement:
- A higher level player is more likely to stay.
- High level players pay/have paid and therefore are invested in the game.
- Higher level players can participate in guild activities that would be hazardous to lower leveled players.
- Higher leveled players won't need as much coaching or helping.
Also, once a guild has a rule such as a level cap, it is generally (my opinion) better to just hold to the standard than to make exceptions here and there. It's the exceptions that cause strife when one person gets preferential treatment and another doesn't. Take DW; they have an adults-only requirement. They stick to that, even though somebody could argue that some younger players could be more mature than some older players. If you have a rule you don't follow or enforce, then you have no rule.
Not saying I necessarily agree with the idea of a level requirement. I'm just suggesting why some guilds could do that. As for the Krewe, we don't believe that age, gender, paying status, and level are indicators of the quality of the player behind the pirate. And some of my lower level players have stayed for a long time while some of my high level players have left.
However, many of my low-level prospects did join, play for just a little while, and I never saw them again. But that's okay. It doesn't hurt us in any way, and if they decide to come back and try the game again they have a guild ready to help.