The title is "why the new gmail sucks" not "a reason gmail has sucked for a long time already". The scanning of content to fuel the advert relevance engine has been a part of gmail pretty much from the beginning IIRC.
If you don't like that, you shouldn't use the old one let alone the new one.
I run my own mail server(s) anyway as I like being in control of the backup processes, having access to recent and archived mail if the Internet has a blip, and being more in control of the interface (I currently use Zimbra, but if they go a direction I don't like I can easily move to something else that supports IMAP but also provides a nice web-based interface). I pay for that in my time (and in having a server to run it on and resource to hold/manage backups, though the cost of that is not particularly high), people pay for gmail by allowing the adverts thing. You pays your money, directly or otherwise, you takes your choice.
Here is a New York Times article on gmail from 2004 discussing the privacy issues around google scanning email content. It is a controversy that came and went, so I can imagine people who were young and not using email at the time missing it entirely.
