The "I lost my keys bro" is the no 1 excuse I hear from those who I helped to onboard here. When a person sees the rewards the site offer they sometimes make an impulsive decision to make an account here and expect the same results from the beginning itself. When it doesn't happen most will likely leave to never return or do even worse like discouraging others as well.
One other thing I noticed after helping them make an account here is the part where I explain how hive works. I usually give them some guides I got from a dear friend here when I was starting here cluelessly but one can see how overwhelming hive can be from the table of contents itself. It was too much information to swallow even for someone with some experience in crypto. I personally would love to see a guide which is more user friendly, perhaps a lite version with the basics only would be great for newbies would be great. I believe if hive improves in these factors I'm sure retention rate will follow.
One another thing I faced while make an account here is that I was one of those users who wasn't very lucky enough to make a free account here. Back then I was convinced that it was worth it because I knew a lot of people already in here who were doing well. I lurked around the site for 3 months before creating an account here until then all the free account creation methods ends up with some IP error. This is also a hurdle sometimes when I try to interest someone about investing in hive community. Some are even willing to make an account and invest here just for the apr.
Since you mentioned reddit I have to say this because some posts are just too long to read. There is a very high chance that most people will skip it so adding a short summary of the post at the end would definitely help them engage better with the author. That's my take on it.