The practice of "Due Diligence" is a responsible precaution, taken by all businesses that have any future as businesses. Blogger / Google, being a business, subscribes to this practice. This affects their involvement with us, their "customers", in various ways - though not all "customers" understand the implications. Some blog owners find out about the limitations unwillingly, in discussions in Blogger Help Forum: Something Is Broken.
One example of due diligence is demonstrated, when we must prove that we are the rightful owner of "our" blogs. Proof of ownership of a Blogger blog is based upon control of a Blogger account. If somebody else gains control of your Blogger account or blog - either by our naive hopes, or by their malicious action - you will have a problem. When you observe a problem, first verify who has control of your blog.
Blogger promises us that our Blogger accounts and our blogs will remain ours, for eternity. That means that they will be diligent in not giving somebody else, who may falsely represent themselves, control of our accounts or blogs. This also means that they will not give anybody control of an "abandoned" URL, when observing that the blog appears "dormant". Nor will they take a forum problem report at face value.
The primary result of this policy is that we, the owners of our accounts and our blogs, must accept the responsibility for maintaining control of our accounts and our blogs.
Since we are allowed to own our accounts and blogs anonymously, we are not given physical tokens that authoritatively identify us as owners of our Blogger accounts and blogs. If we lose control of our accounts, or if we permit our accounts or blogs to be deleted, it is our responsibility to provide sufficient evidence that we are the rightful owner, when requesting assistance.
The bottom line is that, when we lose access to our Blogger account by failing to remember the account name and password, or failing to maintain a backup email address, we're not going to gain anything by complaining about Blogger refusing to help us out.
The needs of the many (active blog owners, who need their blogs to remain under their control) must be considered ahead of the demands of the few (inactive blog owners, who suddenly discover that they have lost control of their blogs). That's good business sense, also known as "due diligence".