Meh.

Measuring support of miners/stakers has never been hard. As you said, soft forks have generally included voting already. If miner/staking voting for mere polls was really wanted and so useful, it would be more widely implemented. No disrespect to the developers here, but it really isn't a hard feature to implement. Miners could even do it on their own by just agreeing to put suitably formatted messages in their coinbase

What makes this whole issue hard is measuring and reasoning about the support various changes would or do have from other stakeholders (using that term as an English word here) who aren't involved with block generation, including possible future participants (who may decline to become participants if some changes are or are not made).

Reducing the entire problem to "(current) block-creators decide everything" is oversimplifying to a dangerous degree.