If people are actually going to make an effort to kick people out to cement their position, then it is better to restrict their access, before they do too much damage. Getting one person who services the need is not worth it if they kick out everyone else.

If the only reason is to cement their position then sure, but there are good reasons to limit the number of admins. The more admins, the more attack vectors for serious social engineering, the harder change control is, the longer meetings go for, the harder it is to make necessary change, etc. etc.

I think if somebody cares enough to become an admin and shows they care about the users then I don't mind them getting a power trip out of it. It's the "admins" that got there because they know the boss, or because they convinced somebody they should have access because their job-title entitles them to it that you need to look out for.