This is a less than ideal result of having the ability to vote on as many proposals as you want. I think the ability to express negation on proposals themselves would be better.
As for setting the bar:
There are 168 Million Hive staked as HP. Of this, only ~24 million vote for the return proposal representing about 14%.
14% is not a sufficiently high enough bar. Especially when the other 86% have to share the outcome.
how much of staked HP participate in proposals governance? all ?
Enough that HBDstabilizer which is at the top, has 43M HP on it. In-fact, when the previous hbdstabilizer proposal was running, it became the effective return proposal, and it too, had around the same bar.