Why is Code Igniter not recommended?

All on CodeIgniter.

That's impressive, could you show us these applications?

starcitygames.com (I did these parts)

• Has a custom CMS system for the articles (including entry by the author, admin approvals, tracking of stats with it)
  
• The entire catalog is built on CI and is extremely flexible:
  • http://www.starcitygames.com/catalog/mag...sh_singles - pulls the main page
    
  • http://www.starcitygames.com/catalog/cat...f%20Tarkir pulls a category
    
  • http://www.starcitygames.com/catalog/Kha...f%20Tarkir if no product is named that, still pulls up category
    
  • http://www.starcitygames.com/catalog/mag...uct/727061 - pulls up single product
    
  • http://www.starcitygames.com/catalog/mag...061/726502 (and so on) pulls up each product
    
  • http://www.starcitygames.com/catalog/mag...ing/727061 - pulls up single product
    
  • http://www.starcitygames.com/catalog/mag...061/726502 (and so on) pulls up each product
    
  • http://www.starcitygames.com/catalog/727061 - pulls up single product
    
  • http://www.starcitygames.com/catalog/727061/726502 (and so on) pulls up each product
    
  • http://www.starcitygames.com/catalog/mag...t/fireball pulls up all versions of a product with this name
    
  • http://www.starcitygames.com/catalog/mag...g/fireball pulls up all versions of a product with this name
    
  • http://www.starcitygames.com/catalog/product/fireball pulls up all versions of a product with this name
    
  • System can support multiple catalogs (mtg is the primary one, omitting that defaults to MTG cards)
    
    
• Multiple payment and combined shipping with existing orders in the checkout, this was a complete system rewrite for the entire commerce system
  
• Suggestive selling upsell system in the checkout (they're not using it to the fullest extent it should be)
  
• Wishlist along with public and private lists
  
• Decklists based on deck type, location and event reporting
  
• Organizer tools (partially by me) to deal with location and events (results under events finder)
  
• Admin tools (you can't see them... duh) to manage orders and shipments and payments
  
• I also implemented the look and feel of the site, updated them from a xcart/legacy system to CI (and several other years of work in the system, these are the highlights)
  

gingrapp.com
These stats haven't been updated recently:
3.86 Million
Happy Pets Served

31.79 Million
Reservations Booked

2.99 Million
Total Users

11.28 Million
Report Cards Sent