千万不要拿自住房当出租房使用,哪是赔钱的买卖, please discuss this

I just sunddently read 各位请注意：自住房和出租房是完全不同的概念。
千万不要拿自住房当出租房使用,哪是赔钱的买卖。

if I moved out and rent out my 自住房, it becomes to 出租房, rental=mortgage, after 15 years, tenant paid off my mortgage, then I will sale my house, do you think it is 赔钱的买卖? please discuss this.