There's been quite a few innovations over the years, and the ones that were lets say.. "less aesthetically pleasing" always found a way to be banned or removed from the cars. BMW and Honda had some of those, in recent memory and they didn't last long.
The reason given usually being something else, like driver visibility or safety, but yeah. It's hard to comment personally on whether this is right or not, because it just is the way it is. There's an aspect of F1 cars that are functional and performance driven and something that is functional can be attractive, separate from the looks of it. Especially if it works really well and is outside the box thinking.
But underneath it all within F1, from the powers that be, there is usually a theme of trying to keep the cars looking good on TV, or in magazines or on posters. When you consider the "aesthetics", it's sort of a hidden rule in the regs.. and it becomes even HARDER for teams to be innovative these days. And the designers like Newey complain enough about that as it is. There's nothing stopping a team from doing it, but within 6-12 months, it's highly unlikely that the new part will still be on the car. If it's really ugly it might only last a few months before it's banned.
Innovations and variations between the cars are good though. These days most of the cars pretty much look the same to me, so I get a kick out of launch topics when people discuss the differences and get excited about them, because they are so minor. The airflow around the car and minor details might be different but the wing shapes and general concepts seem quite similar. They are all pretty much clones of each other, very similar to a spec series. It's not a spec series but the regulations are so tight, so that it's like a semi spec series.
It's under the hood, where the bigger differences seem to lie. It's hard to argue against teams being able to innovate and have original shapes and differences that separate them, but at the same time.. people are always talking about liveries and ugly noses and things like this. So it's an interesting balance. To me open wheelers in general aren't very attractive it's a pretty weird shape, it's the performance and driving characteristics of open wheelers that I find appealing.