I don't get it, how can the Miners cause the most pain? From all the bad stuff happening caused by minor factions, these are on of the easiest to deal with. Or is that the whole point? Personally I think 30 mins is at least 15 mins more time than you need to deal with them in most cases.
Because they're so random in placement 30 minutes may not be enough time to drill yourself a deepstrike hole to even reach them, particularly in the early game.
This, and it is literally a negative sum game.
There is no way for the option to have a benefit. And if you lose you get a very nasty
aip econ hit and a lost planet for supply, and if you "win" you buy a little time as you lick your wounds from a deepstrike and the ai response.
Some things are a negative sum game, but don't cause aip or econ lost in any way (hybrids). Some do cause an aip hit but provide a benefit (rebel colonies). Miners have the nasty position of both the big negatives.
If miners had a side chance for a benefit, say, miners that somehow mine asteroids instead of planets (which in term can somehow give resources to the player) but the ai does notice them so the player must protect them, or if the miners somehow hurt the ai in any way aside from lost supply, then I think miners would get a lot more attention.