Nothing is wrong with keeping bettas with guppies. It's all a matter of opinion and personality. Guppies and bettas can be fine if the Betta is docile and you have a backup plan. Please next time, instead of leaving something negative about someone else's tank at least stay on topic as well. I'm sure you wouldn't like it if I commented on the way you keep your fish. Getting totally of topic. I removed your comment from my link to the page as I felt is was poorly supported by research. Of you'd like more opinions from more expirenced members I will freely show you how OFL, and others say its okay under certain circumstances