To me, many of these ideas for a different points system just seem like a bandaide to add a sense of excitement to rather dull seasons.
If we were in the midst of a season where up to 8 drivers or more had legit chances of winning races, the points would look very different and discussions regarding the system would be very different. To me, that's an indication that there's something wrong with F1, not something wrong with the points system.
I also don't think the arguement "look at the lead Rosberg has after only 5 rounds," is a valid reason to change the system. Yes, his lead is big. But as things in F1 stand right now, he is one of two drivers who are heavily favoured (we'll see if things change in Monaco and Canada) to win, and his main rival has had some poor luck.
If Hamilton had finished 2nd to all of Rosberg's wins, then the gap would be smaller, and in theory, Hamilton would just have to echo Rosberg with 4 wins of his own to tie the championship.
The fact that both Hamilton and Rosberg DNF'd in Spain is just another case of the strange circumstances that have taken place so far this year. If Hamilton would have won while Rosberg DNF'd, again, the points would look different, and the discussion would be different.
Let's imagine a hypothetical season, under a 22, 21, 20... point system. Let's say Rosberg wins the first 4 races, and Hamilton finishes 2nd each time - giving Rosberg a 4 point lead. Now, let's imagine at round 5, Rosberg gets Maldonado'd by someone and DNFs while Hamilton wins - which would give Hamilton and 18 point advantage over Rosberg. 18 points, with only 16 rounds remaining!! Rosberg could literally win every single remain round (imagining a 21 round season), and all Hamilton would have to do is cruise to 2nd in every race and still win the championship. You would have 20 wins with one DNF finish second to 1 win and 20 2nds. That just doesn't sit right with me.
With the current system, if a driver has a poor result, they can still take significant chunks out of a rival's points total by winning races. In a system where the points difference is minimal between positions, it becomes increasingly difficult to recover from one bad race. On one hand, I like the idea of consistency, but not if the trade-off is that one bad race can ruin the season (and let's face it, we all know "one bad race" can happen for a million reasons, many of them completely out of the driver's control).
Any sport where there is a championship table, with points awarded after each event, is always going to lead to scenarios where the "champion" is decided before the final round more times than not. Hockey, Baseball, Basketball, Football, Soccer....this happens almost every single year. Often times, top teams barely compete in final games once they've locked up their position. The reason we celebrate seasons which come down to the final minute of the final game is because they are rare - and that's what makes them special. Also, the reason we don't get too hung up on teams clinching titles before the end of the season is because in most other sports, there are playoffs, with a completely different type of rewards system. I've tried to wrap my head around the idea of playoffs in motorsports, and I just can't warm up to it.
So like I said, I don't think there is much wrong with the points system - the issue most people have, in my opinion, stem from problems due to the lack of real competition in F1, and not from the way the points are handed out.
Edit: just as an aside. Under the current system, with his win, Max went from 10th to 6th in points. Under the 22, 21, 20 system, he went from 8th to 7th. At this point in the season, a win gaining a driver 1 spot in the standings doesn't sit right with me.