Any improvements in exporting data from a Google Account that will make a daily backup actually doable are welcome. But Google should not place all responsibility in the hands of the users, since this inevitable will result in bad user experiences and therefore bad publicity.
Regarding spammers and phishers, these are users violating the law and they of course have no legitimate claims to their account data.
The backup methods are very different for each Google service. If you want daily backups of all your Google services, you need to pay for multiple external backup services and/or spend a lot of time doing it manually.
And how do you download all your Google Analytics data? This page on the Data Liberation page suggests that you export to XML, Excel or TSV. http://www.dataliberation.org/google/analytics
But to do daily backups of all the dimensions, metrics, advanced segments etc. would be very time consuming.
You could do it easier with the API, but that requires programming knowledge.
It is not realistic to expect all users to continually make backups of all their Google services.
It is however realistic for Google to solve this by putting a violating account in a "read-only" mode, where you are able to export all you data and not do anything else.
Regarding spammers and phishers, these are users violating the law and they of course have no legitimate claims to their account data.