What it all comes down to is a matter of principle. While today's written laws and policies can be skirted around to avoid paying for this type of damage, and it's true (at least for the time being) that most of the time no one is going to get hit with repair costs, we're getting into a gray area of ethics when you're talking about renting a car for chasing. What goes around comes around, especially in business. While there may not be consequences now for returning a damaged car, if you do damage a car, you're costing other people money who, one of these days, are not going to just let it go.
I worked on a huge website about insurance and (involuntarily) learned a ton of stuff about the industry. Insurance is about risk - that's the bottom line. When you purposefully drive a car in the vicinity of a supercell, there is a much greater risk for damage than the family taking their car on vacation, for instance. Today both types of renters pay the same amount for insurance, but as we are seeing, that is starting to change. Yes, hail can be avoided, but it is unrealistic to plan to avoid it entirely. Chase for long enough and you WILL get a few nice dents. In fact it will probably happen every year for most of us (raises hand). Hail isn't the only thing - there are flooded roads, muddy roads (and the likelihood of getting mud inside the car from shoes), wear and tear from driving 15,000 miles or more (that alone is taking ~ 1/12 out of the life of the car), and the wear on the *inside* of the car from practically living inside it for weeks. Don't even get me started on those Kansas towns with the huge drainage dips on cross-streets that you don't see until you've done a bottom-scraping General Lee across them (remember that one, Kurt, Nick?). :shock:
Also, as mentioned, your *own* insurance is going to go up if you make a huge claim on a rental. I'm just saying there is no way chasers can keep putting thousands of dollars of combined wear and tear and damage to a rental car, while only paying a couple hundred dollars, and there not be long-term consequences. You may get away with it now but it can only go on for so long. I've chased for 12 years and I know what my car has to go through on an average chase trip. I personally think renting a car for chasing is taking a huge gamble. I'm not knocking anyone who does, like I said sometimes you have no choice - but I guess I'm trying to say it is more of a risk to your personal finances/insurance risk category than it we are making it seem.