In effect, BB Personal was not designed for advanced users it was designed for people who just want good cloud backup to automagically happen. The most hopeful is here - a well worded search would probably reveal more of his eloquent posts.

U/brianswski has written about this pretty clearly in the BB sub. However someone making a linux software for Ubuntu linux using GTK, KDE or QT framework, they could easily replace whatever random number generator the Linux API uses, and swap it out for their own to bypass or override it, in a way that is so inconspicious, that anyone looking out for it would be nonethewiser. If the Windows API has a feature for windows software developers to generate realistic random numbers, there is no way that can be modified without it being detectable somewhere down the line. Creating a detection software to detect for abuse wouldn't work on an operating system where it's expected that every piece of software is open source. Why doesn't Backblaze just create software that can detect if Linux is being used for server usage or consumer usage, along with detecting mounted network drives and NAS? Linux is open source and Linux distro developers, Linux software developers and linux users tend to be open source PURISTS who reject all closed source software. They have calculated how much money they would lose if they supported linux for personal unlimited backup and it was so much that it wouldn't be financially viable, not just not cost effective. Backblaze calculated that it costs them $7 a month to store 1TB and with the majority of windows and mac customers only storing 1TB, there is enough low usage customers to compensate for subsidising the high usage customers. If Backblaze was to release a linux client, people would use it to backup their servers instead of their personal computer. The reason why is because windows and mac is primarily used by consumer usage and linux is primarily used for server usage. Just do a search before asking your question. This has been asked on this subreddit countless times before.

Backblaze linux client