I'm not surprised. Stories like 'this lady lost 40kg' or 'this family of six paid off their house in 5 years' are almost always met with 'I couldn't do that because [weak excuses]' or 'they were only able do this because of luck'. Not to mention a lot of them seem to think of it as an all-or-nothing scenario. In their mind, you HAVE TO work three jobs AND have housemates AND eat nothing but rice and beans AND have no social life, then of course you'll pay off your house!
It is still pretty amazing to see so many people taking offense at how a complete stranger chooses to live his life. I wonder if the average commentator also gets angry at wealthy business owners and people who work on oil rigs because they "can't" start their own business or "can't" work on an oil rig.