In my area lots of landlords do interest only mortgages. I don't recall anyone saying it was hard work all the time. Only that it is work and that there is nothing wrong with taking a reasonable profit for that work. Plus when things go wrong it can be both very stressful and a lot of work. Its not all easy going and sitting back counting the profit. You have to factor in all the things like when the tenets trash the place and refuse to pay.Are interest only mortgages even possible on B2L? That doesn't seem like something a bank would sign up for unless the mortgage rate was astronomical. The risk to them seems rather high.
Oh and not a single person I know who has a single second property thinks that its a job or that its hard work for the money.