This is covered in the pinned threads:
Not really. Many ISPs share routing partners, so it could be one routing partner causing a problem. Blizzard probably doesn’t investigate that because they aren’t the ISP’s customer. They have no right to service or help from them. If you pay an ISP money, you are the customer and can ask them to investigate.
Unfortunately, after working in telecom for more then a decade, I know that most ISPs don’t care if you can connect to everything or if you have packet loss causing disconnections. They can explain it away as normal network fluctuation, and most of their terms of service details include leniency for that.
That system is something players asked for because leavers are/were a horrible problem. You can leave feedback about it in General Discussion or Competitive Discussion, but I recommend not disparaging the staff if you want to be taken seriously.