I'd like to try and give you some sympathy, but my last landlord was a well-regarded property management firm who left me with no heat from the end of October to the weekend of Martin Luther King Day in New England, effectively only fixing it once I withheld rent, got on the local news, and was threatening a lawsuit. So, uh... yeah plenty of landlords have done a lot to earn that reputation for the class as a whole.
That's true, but I think when you pick a place to live in, you're not only really only interviewing the living establishment itself, but also the landlord/property management associated with it. I make an effort to do all of the tours of the units myself and establish good repoire with the tenants from the get-go. It's certainly inexcusable if a landlord doesn't fix things that impair living conditions—in Seattle we have a law that things of this nature must be fixed within 48 hours which I think is a reasonable law.