It's only a problem if you decide that her feedback about your property is important to you.
I don't know, you can still take their input and consider it important, but just ignore it because it goes against what you want to do with your things. I think it's a bit heavy handed to say it shouldn't be important. I'd still ask my wife out of courtesy and to get her perspective if I was going to do something drastic, she might have some useful insight. If she flat out said no or didn't have any useful input such as, "why just one? Two horns would be louder.", I'd likely take her protest into consideration, but would do what I wanted anyway.
I'm also married (only the one time over 8 years to a women I've known for a total of 15). The dynamics of anyone's relationship is really their own business and if it's working for them no one should judge.
We keep our finances separate and divided the bills up more or less evenly so whatever is left over is our individual spending money. I bought myself a car, outside of the regular bills, almost 10 years ago and I let her use it. She's only complained to me once because she wanted to take it to her parents place for the weekend, which would have left me stranded on a weekend where I had a ton of things to do. She told me I could take the metro bus around town, which I wasn't particularly happy with, and a little angry she even made the suggestion. It would have required two days to do an afternoon's running around. Not to mention the difficulty of transporting things, including lumber, or having to run out on the spot if I was missing something. There was some discussion about it that got heated and nearly ended with her losing all driving privileges. We "compromised" and she got a two-way bus ticket so she could go to her parents and I'd have the car. The compromise was I'd let her keep using the car if I didn't need it.
Every now and then I remind her the car is getting up in age and we'll have to get another one. I've been saving knowing it's coming and don't need her help to pay for it, but I give her the option so she'd have more of a say in how it's used. She's happy enough with the arrangement and knows unless she pitches in for it there's no expectation she'll just get to take off with it whenever she likes. I know it sounds like a harsh arrangement or that I don't respect my wife, but that's not the case. We get along great, real couples know marriage is a team effort, but that doesn't mean you have to let your spouse call all the plays all the time and you shouldn't just let them walk all over you. She gets to win her share of the battles too.
most women I've been with would rather take your shitty stuff for free than have to buy their own.
This part I agree with, but it's not exclusive to women. Friends do it too, mine (including my father) are quite happy to come over and drink my shitty beer without even offering to pay for another kit or bring any with them. But I'm compensated with the company and entertainment, which is really the same thing with marriage, except there's sex too.