Unnecessary stylesheets frontend

Currently got this plugin installed, so my client can influence the order of a custom post type as well as the pages.

Functionally speaking it works great, however I had a question regarding the stylesheets that are loaded in the frontend (five stylesheets!).

This happens in the mpto_post_listing_styles() function in multiple-post-type-order.php. It concerns the following code:

wp_register_style('post_listing_css', MPTO_DIR_URL . 'css/post_listing_css.css');
    wp_enqueue_style('post_listing_css');
    wp_register_style('main_css_file', MPTO_DIR_URL . 'css/pmto_dem.css');
    wp_enqueue_style('main_css_file');
    wp_register_style('main1_css_file', MPTO_DIR_URL . 'css/normalize.css');
    wp_enqueue_style('main1_css_file');
    wp_register_style('main2_css_file', MPTO_DIR_URL . 'css/style_one.css');
    wp_enqueue_style('main2_css_file');
    wp_register_style('main3_css_file', MPTO_DIR_URL . 'css/style_two.css');
    wp_enqueue_style('main3_css_file');

I dequeued these stylesheets in my functions.php file, since they conflicted with my theme.

The website still works great and so does the plugin, so I wonder why these stylesheets are added in the first place?