If you are the first person to enter an RG you have to wait for 49 others to enter and perhaps as much as 12 additional hours before you can go on to your next RG. This might mean waiting several days or perhaps even more depending on the popularity of the RG. Obviously the best circumstance for you, personally, is to be number 50 so that as soon as you finish your round you can go on to the next one.
Naturally waiting to be number 50 before entering a tournament will prove difficult and might limit the tournaments that you choose to enter, but at least you will know that you don't have to wait up to an additional 12 hours if you choose to play immediately.
Otherwise accept that some people entering RG's might wait before posting scores.