It's even simpler to not care - somebody using 10minutemail wouldn't react anyways, thus they send out some automated mail after a while and if there's no reaction kick the address of their active leads ... tracking down invalid mail domains is effort, sending out a few mails more is no effort.
Cockroach is a DB company. Customer acquisition cost is in the thousands if not tens of thousands or hundreds of thousands.
The steps I mentioned above are what, maybe a few hundred dollars. Trust me, their lead generation pipeline most likely already subscribes to this and utilizes it with minimal concern.
There are plenty of CRM tools that can flag out BS domains and/or low value not worth it domains.
If you are a person who gets by using 10minuteemail, you are not their target market. So will their target demographic.
The extra hop is very necessary for prevalidation. And they will be just fine with it.
You on the other hand, being the cheapskate that you are, have to commit an extra 5 minutes every time you generate these BS emails. Obviously you don't value your time as much. And that is why, again, you are not the target market because you extract no business value from accessing the knowledge they spent time and money aggregating for you. Your getting the PDF is inconsequential to both them and yourself.
So go ahead, no one really cares.
EDIT: Lol, you was not referring to you specifically, just the folks who think they are being smart or outsmarting corps by using these services like 10minutemail or whatever it's called
I am squarely in their target demographic and yet refuse to provide my email. I like keeping noise low in my work inbox - if I will decide I'd like to buy something from cockroachDB, I'll approach them. It's purely negative value to have them approach me - I have never received any useful messages by being on a marketing list.
It takes way less than 5 minutes to generate a temporary email address.
Also, I fail to see how refusing to provide your email address correlates with frugality. If anything, people who are cheapskates would be happy to pay with anything but money.
Ad budgets are much bigger portion of acquisition cost than content marketing. Do you have an equally emotional reaction to people who decide to use ad blockers?