Despite mid having more potential for early kills before bottle crowing, it doesn't make the lane any less interesting to watch. As much as you can regen fairly effectively with a crow, as others have said, it means you are more likely to miss runes, which not only effects your effectiveness in your own lane but means you're allowing the other player to top and bot more.
Personally, I don't see the problem with bottle crowing. You may see less kills in the mid lane, but since the two mid players are generally going to have a higher average mana/hp pool than if they weren't crowing, the likelihood of ganks to sidelanes increases thanks to crowing, which somewhat balances that out. Despite people saying that people play it safe in mid these days, I am yet to see a single pro match where the two mids aren't constantly looking for openings on each other.
I'd rather see varied draft choices and interesting hero match ups in mid to be honest.