Thanks all for the good discussion. To answer Kevin's question, yes, there were cases of spamming and misinformation that TechNet managed to mitigate because they were public. It's impossible to know however if some accounts try to spam via direct message.
The TechNet platform has always been open to all, and the bar to have an account approved is low as it's sometimes difficult to know if the person who creates it is who they say they are. Still, 99% of the people who apply are approved. In that context, improving trust can have a benefit on the platform; it can improve trust when necessary, in particular when exchanging private messages with someone you never interacted before, and if the relationship implies something transactional (e.g. getting in touch with someone from a company to buy a product, exchanging personal information for a potential recruitment, etc.)
Being verified doesn't give additional rights or power on the platform, it's voluntary, and it doesn't mean one account is superior or inferior to another one. It only means a user wants to make sure people know they are who they say they are. Verification really doesn't change anything in terms of how users can interact with the platform, and a user who is just interested in reading or posting once in a blue moon doesn't really need to be verified, frankly. Users who want to interact more with other users to build a network, exchange information publically or privately may find it useful.
Regarding criteria, in reality, any criteria that allows us to verify an account works. Verification is verification, the only thing that is needed is that we can ensure that a person is who they say they are. So if someone really wants to be verified and doesn't meet any of the criteria mentioned above, they can still interact with the moderator, and a solution can be found, as long as they can show they are the real person behind the account they manage.