We've been through this on some other manga's forum thread, but fan TLs still have this agreement not to impede on each other's projects. =/ It's just more efficient to have 2 groups work on 2 different works rather than on the same one.
It's not like they're getting paid. Well some of them do run patreons and ads on their sites.
Most do this because they want to. Just because they aren't doing one manga doesn't mean they will work on another, or choose one you would want to read.
They don't owe the readers anything, will drop manga whenever they want and go months without releasing things. It's not some organized professional thing.
In that atmosphere I think it is silly to think you have a right to or are owed some deference. The only groups I would say that have earned that courtesy are those that keep a consistent release schedule that doesn't lag farther and farther behind the original.
Imagine your hobby is model rocketry you read something about a new rocket or engine and decide you want to try and make it. Wouldn't it be silly to get upset because someone else made it first?
Let's say you even publish weekly youtube videos documenting your progress. Wouldn't it be silly to think that means no one else in the world has the right to do the samething?
That's what scanlation is, a hobby, something you do because you are interested in it and want to do it. Just because someone else releases a manga translation doesn't mean you can't do your own version and share it.
And if someone else releases faster and a better quality version than yours, why should readers be saddled with an inferior product just because you got there first?
I was all over the place, but that is why I think the whole thing is silly.