However: Those who use other scripts than those benefitting from the additional discount would not be punished at all.
It really depends on how you look at it, you may call it a 50% discount or you may call it a 100% tax, being on the "normal transaction" side, it would seem as though you are getting a 50% discount compared to the rest, being on the other side, it would seem that you are paying a 100% tax compared to the rest, if we think of block space as goods sold at the market, at the end of the day, a "normal" person can buy twice as much of those goods with the same money compared to those "weird" people.
However, I agree, censorship is probably not the best word to use here, I suppose it's more of a discrimination.
Miners would probably not necessarily against such a policy: while the average fees would level down a bit, there are more transactions they could fit in a block, so the total fees collected per block could increase. A
This is a "Chicken-and-egg" debate, and has not been solved, and probably never will, simply because there are two side of the same story, the first one is what you described, in other words, more space = more transactions = same or more profit for miners.
The other side suggests a different thing, because you are creating more supply of something, it's most likely the price will go down, and that makes sense because you can't guarantee "demand", you would only speculate the demand will go up, which isn't something you can be sure of, and if demand doesn't increase as much as the demand does, then the overall price of block space will go down enough to bring the overall profit down.
people who support this theory have a very good point, and that is, whoever needs to transact on the blockchain would do so no matter what the fees are, and those who don't want to transact on the blockchain -- they won't even if you bring fees down to near zero.
The above "theory" suggest that the transaction count is limited, so you could just assume that there would be 100 transactions a day no matter what, if there is enough space for all 100 to be included on the same day, you are simply removing the competition/bidding insetnive, whereby if there is only a place for 10 transactions, those 100 transactions would have to outbid one another, raising the profit of the miners.
Keep in mind that in order for profit to be the same for miners in the above example, if you increase the daily block size from 10 to 20, and want to keep the same profit, you would have to increase transaction count by 100%.
So
10 space > 100 transactions > profit = 1
20 space > ?? > profit = 1
=
20 space > 200 transactions > profit = 1
anything short of 200 will make profit < 1.
And it's not guaranteed (actually probably less likely) for transaction count to do 2x just because fees are down 50%, so this side of the "Chicken-and-egg" theory is more favorable to most miners because they can't control demand, they rather control the supply.