Getting rid of a way to truncate long reply threads seems like it might cause other problems. For example, if folks are sorting the comments by what's most popular (which is a handy feature) and there isn't a way to truncate the replies, everyone who replies to the top-most comment has their post appear above everyone else who simply posts to the main thread. Something like this: 

1. I'm the most popular comment! 
     a. response
     b. response
     c. response
     d. response
     e. response
     f. response
     g. response
     h. response
     i. response
     J. response
2. I'm the second most popular comment.  
     a. response
     b. response
     c. response

Imagining a scenario where the most popular comment has 200 responses on it, this could be a real pain. 

Perhaps seeing the four most popular responses to each comment could be done? I'm not sure.