I'm glad you put this out here. I first encountered this issue when trying to vote @steemgigs for witness. I think the first time, I left thinking the name is not available. I don't even understand how Steemit Inc arrived at that decision of keeping only the top 50 on the witness voting page - it's quite bad. I didn't know how to reachout to anyone on this issue as am still comparatively new on the platform.
This is exactly the same issue we have when it comes to elections here. Those already in office, use the state money and influence to run excessive campaign and put their name in everyone's mouth that 80% of the populace do not even know that there are other candidates.
I suggest either the system becomes unfair to every witness by removing all the names from the list and we'll have to search everyone's name or it becomes fair by listing all the names of witness. I know the name might be pretty much but it's okay as long as people see that next page button which tells them that there are more names. I hope this post gets to appropriate quarters and something is done about it.