You have met the second one now
Currently, I am working with a few teams who are doing Scrum and have adopted Scrum and staying true to the spirit of Scrum. I have been a ScrumMaster for several teams in the past 7-8 years and have seen that these teams have sustained and have been following Scrum successfully.
Some teams have been successful and some not very successful.
The teams who have failed were the ones who didn't stay true to the spirit of Scrum, or have adopted Scrum partially or have develop anti-patterns while adopting Scrum. One of the other big factors was not having the management support.
The teams who were successful were the ones who follow the rules of the , frame-work, ensuring all the events (meetings) happen, artifacts are created and roles defined/followed.
In my experience, I felt that the organizations I worked with created a safe atmosphere for Scrum teams to thrive. The teams trusted each other and also followed the values of Scrum - Courage, Openness, Focus, Respect and Commitment.
As they say, Scrum is not a silver bullet or it's not easy but if we stayed focused and inspected and adapted, teams will definitely be successful.