We have Ansys, Synopys, Mentor,Cadence and Ailent ADS tools. Based on my experiences about the support site, A fact is that all vendors never allow out-of-maintenace user to access thier support site except Agilent. So I think it's just a common policy in EDA indutry that only users who are under valid maintenance be allowed to get access support site.
Agilent(now Keysight) is an expection and even you aren't a Agilent user, you also be allowed download ADS directly from the site.
Volain - Thanks for your investment in and use of Mentor tools, and thanks also for your question. It is a good one, and others have likely considered before.
As suggested by Yanfeng's response, many other companies understand that technical content like TechNotes and AppNotes are another aspect of technical support, similar to phone/email support for service requests. Mentor Graphics shares that perspective.
TechNotes and AppNotes have been created by our Customer Application Engineers (MGC's term for Support Engineers), and there is a direct cost to create those -- time spent researching a solution, developing the content, and ensuring its accuracy. Each TechNote and AppNote can take a considerable amount of time. When multiplied across the thousands of TechNotes available to our active support customers on SupportNet, you can see that this is a considerable investment by Mentor. Just because these resources can be available online doesn't minimize this expense in any way. These investments are funded by our customers' ongoing support contracts. Mentor Communities offers an alternative where users can help other users directly, find insights from posted discussions and documents, and sometimes engage with Mentor technical personnel. And this is available for Mentor product users that are either on active or declined support.
BTW - we will soon be rolling out a new version of the communities with many new features and improvements. Stay tuned for more information in the coming weeks.
If you have any further questions, please ask!