As someone who worked for another German webhosting company (not mentioned in the article but more than a million customers), I can tell you that it's extremely hard to roll out new versions of typical software (PHP, Perl, MySQL) when you both want to keep your users on the latest (or a reasonably recent) version while not breaking your users' websites. And because there will always be customers unwilling or unable to switch to later versions, you end up running Perl 5.6, PHP3&4, Frontpage Server Extensions (yes, people still use that stuff) and MySQL 4.

That said, Uberspace is still small enough to take care of their users individually when it comes to support. They can keep their architecture simple (well, so does 1&1, but rumor has it that they have 100 people working in their data center only to replace broken parts in their shared webhosting system), and text-only configuration files and not fully automating everything is still feasible and doesn't hurt yet.

Scaling webhosting while keeping up good customer service is hard. That's why your experience with small hosters will often be better.