Views template files not working
Best way to learn something new about your project is not to ask "what is going on" but do own investigation. Try to debug as much things as possible. You can start by enabling Theme debug mode This is great feature implemented as of version 7.33

As Drupal documentation states:


  As of Drupal 7.33, Drupal core has a theme debug mode that can be enabled and disabled via the theme_debug variable. Theme debug mode can be used to see possible template suggestions and the locations of template files right in your HTML markup (as HTML comments). 


Place $conf['theme_debug'] = TRUE; variable in your settings.php file and use Developer Tool (F12) in your browser or any other tool that can help you see source HTML markup.

With theme debug mode you will be able to see all template suggestions and what tpl file was chosen to rendering. If your tpl file is really rendered you should see something like:

&lt;!-- BEGIN OUTPUT from '(...)/views-view--travel-extras-hotel-carousel--block.tpl.php' --&gt;

This way you will discover the cause and learn something new about your Drupal project.

Remeber to clear cache (at least theme registry cache) after each change connected with template files. This assures that your theme "knows" about tpl file. The same applies to preprocess or hook functions.

Remove mytheme_preprocess_views_view - try to solve initial problem first.