I have been working with Drupal for over six years now, for much of that period exclusively working with Drupal as an employee or in a freelance/contract role.
Prior to the start of Drupal 8, the nearest thing I manged to getting off of the island was periods of doing something completely different (Expression Engine, Django, a custom PHP framework, attending a Silverstripe conference), usually because of an existing or already started/inherited project connected with the Drupally people I was working with.
These sabbaticals were reasonably short, however often instructive and enjoyable, in some cases (not all) the feeling was 'could have been better done in Drupal', they were a complete break from Drupal.
I have just finished ten months of working on a Symfony based project and things are very different.
Bursting the Drupal Bubble
For almost a year, I have not been doing Drupal, but also so busy and involved learning more about Symfony, Angular 2 and other technologies that I have not had time or capacity to attend Drupal events, meetups etc.
Although working with a group of people that had all used Drupal a lot before (amongst other things), Drupal was very rarely mentioned, not one person said 'this could have been done better in Drupal' in fact the only time that really came up at all was in reference to other client systems that were integrating with what we were building.
I needed to burst the bubble, forget about Drupal and whilst working on something different spend my time thinking about that.
The bubble I am referring to is thinking about everything in the context of Drupal, even the proudly invented elsewhere bits in Drupal 8. This kind of thinking can perhaps have the same bad effects as the echo chambers on social networks where everyone you are connected to has essentially the same or similar references and experiences.
There is a possibility that the next contract I do will not be Drupal either.
Drupal is still there
Using Symfony and anything using Symfony components (Laravel may be next) still increases knowledge and skills related to Drupal (before 8 anything elsewhere just meant Drupal relevant knowledge was fading over time). Having used the Symfony console a lot and written commands for it, I will be pouncing on the Drupal Console when I do my next piece of Drupal work for example (which is more than I can say for Drush).
I am clearer about what I think Drupal strengths are though. I current have two personal projects I want to start/finish, one is a match for Drupal one for Symfony.
Mileage may differ for other people, I found I had to put Drupal to one side for a while, it is all very well getting off the Island but that is not quite so effective if you remain in an Island culture ghetto somewhere on the mainland and don't fully integrate for a while. Some people will have no need to ever get off at all, we all have different stories to tell.
However if you do come across some work that would be better done in something else, will you even know? If you do know will you have the courage to burst the bubble?