Actual good question, it's "Let's Love" popular because it is a very generic shoujo manga because it's not... really that distinctive (according to the editorial department of the Romance magazine)? *thinking emoji*
...then again, I think of a couple of IRL shoujo series that are popular and I cannot, for the life of me, say if they are truly unique or not (and other fall into typical drama cliché traps, even).
I would have gone for cooking manga. Good thing for Nozaki! The dude is alread ya great cook, it wouldn't be that hard to incorporate that in the series ( and good for Maeno??? if they went through the Food Wars!like route...).