It's not slimy, it's called normal compromise, and it's been a basic building block of politics for thousands of years, but is often seen as slimy by people who are naive about it.
If you and I are arguing and I want X and you want Y, and can only afford one, a logical compromise is to have half of X and half of Y. That's what combined bills basically do -- package together unrelated things, which seperately, would have to be voted down, because the reds would vote down X by a slight margin, the blues would vote down Y by a slight margin, and nothing would ever really get done if you kept issues unbundled -- but by bundling you are able to achieve GETTING THINGS DONE THROUGH COMPROMISE
If you and I are arguing and I want X and you want Y, and can only afford one, a logical compromise is to have half of X and half of Y. That's what combined bills basically do -- package together unrelated things, which seperately, would have to be voted down, because the reds would vote down X by a slight margin, the blues would vote down Y by a slight margin, and nothing would ever really get done if you kept issues unbundled -- but by bundling you are able to achieve GETTING THINGS DONE THROUGH COMPROMISE
For more information, take a basic high school course on government and politics, or read some history eg https://www.amazon.com/U-S-Government-Politics-Prep-Plus/dp/...