Because I have an innate dislike of having multiple types of the same ore cluttering my inventory up early-game. And I don't want to confuse people with the old 'Hey, both of these say 'tin', why aren't they stacking' issue.Why would you remove some of the more innovative features of this mod? And also, blue slimes are not bad for specific tools. But the gravel thing is just interesting and new and unique and very friendly to people who are slow to start a base, the way many novices will be?
Probably because they are instant death, and even moreso in the Nether since now they are likely to blow you into lava assuming you survive the explosion in the first place.And Nitro Creepers are just such a wonderful add to the nether... Why do they bother anyone now that they're not overworld spawns?