It really wouldn't matter unless it was enough of an expense to make itemizing make sense. Many people in the country don't even itemize their mortgage interest (where the amounts of mortgages are high it makes sense to itemize of course). I think at one point ALL interest was itemizable, which may have encouraged debt but was at least fairer. I didn't until recently realize what a total scam the mortgage interest deduction was*. I really thought it was just for buying houses (condos whatever) ok. I didn't realize you could basically get a deduction for anything by using Helocs and the like, but I think maybe you can. If that's true then it really would be fairer to make all interest deductable rather than having to launder interest through a house first, that is completely ridiculous.
* I didn't until recently understand what student loans were used for either. I thought they were used to pay tuition and books (duh) I didn't realize people actually used them for living expenses! I guess I'm pretty naive in many ways.