So are you saying you encounter one of these people more than once out of every 20 runs? Careful, before you immediately hammer that out that they're in "soo many DF's" think hard. Negative experiences tend to stand out and we tend not to remember the other 200 runs we did that went smoothly and were just another 12 minute DF.
Maybe it's my data center but I find actual non-contributory people to be incredibly rare and people who don't respond to gentle coaching even rarer.
The simple presence of "easier" roads to endgame don't necessarily mean there is an epidemic of people who want to be carried. There is an overlap with people with actual disabilities, limitations and those who play only for the story and organize their own willing carry parties who you'd NEVER meet in a DF.
Why is that too many just because you increased the number? 5% is 5%. Chances of encountering those people remain the same.