I run a rental business and purposely purchase products that I need for personal use such that it can be deducted as a rental expense. As long as I use it >50%

I run a rental business and purposely purchase products that I need for personal use such that it can be deducted as a rental expense. As long as I use it >50% for rental stuff it's tax deductible. Should I feel bad? More specifically, does this violate the "spirit of the law?" Even more specifically, every other rental owner does the same thing, so even if I change my behavior, I'm at a disadvantage with my competitors. Again, your issues are with the government, not the companies that are following the law.