Magento 2 Install Script – Fix InstallData.php Not Running Again After First Time

Try the following way:

namespace VVV\Comercial\Setup;

use Magento\Customer\Model\Customer;
use Magento\Customer\Setup\CustomerSetup;
use Magento\Framework\Setup\InstallDataInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\ModuleDataSetupInterface;

/**
 * Class InstallData
 *
 * @package VVV\Comercial\Setup
 */
class InstallData implements InstallDataInterface
{
    /**
     * Customer setup factory
     *
     * @var \Magento\Customer\Setup\CustomerSetupFactory
     */
    private $customerSetupFactory;

    /**
     * Init
     *
     * @param \Magento\Customer\Setup\CustomerSetupFactory $customerSetupFactory
     */
    public function __construct(
        \Magento\Customer\Setup\CustomerSetupFactory $customerSetupFactory
    ) {
        $this->customerSetupFactory = $customerSetupFactory;
    }

    /**
     * {@inheritdoc}
     */
    public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
    {
        /** @var CustomerSetup $customerSetup */
        $customerSetup = $this->customerSetupFactory->create(['setup' => $setup]);

        // Add new customer attribute
        $customerSetup->addAttribute(
            Customer::ENTITY,
            'is_commercial',
            [

                'label'                 => 'Commercial user',
                'input'                 => 'boolean',
                'required'              => false,
                'sort_order'            => 900,
                'visible'               => true,
                'system'                => false,
                'is_used_in_grid'       => false,
                'is_visible_in_grid'    => false,
                'is_filterable_in_grid' => false,
                'is_searchable_in_grid' => false
            ]
        );

        // add attribute to form
        /** @var  $attribute */
        $attribute = $customerSetup->getEavConfig()->getAttribute('customer', 'is_commercial');
        $attribute->setData('used_in_forms', ['adminhtml_customer']);
        $attribute->save();
    }
}

Make sure your module is deleted from setup_module table before run setup:upgrade

For debug, you can user error_log or magento log system for checking, it's running or not when you install module.

You should use Magento\Eav\Model\Entity\Attribute\Source\Boolean source instead of 'Magento\Config\Model\Config\Source\Yesno'