Full Advantages and Opera

What does it means that You Suggest me to use firefox\IE(...)\safari(?!) and deny to access by Opera??
If you prove to access by Opera (gmx.com) you can see that all works great. Opera respect 100% the correct standards of web development and transform in a pleasure surfing the net.
>> Why is Opera less popular? Only because it had not sold itself to companies and their promotional toolbars (as FF & IE).
Opera is genuine and does not copy as Google Chrome that have taken all the credit of most important Opera' s features.
More sites blocks Opera to accede, but their programmers are so stupid that if you mask Opera as IE or Firefox (from a button!) you can overcome this block.
Finally Opera is free.

------->> Suggest Opera, don't deny access, Please!
you can only create inconvenience in those use it

p.s. : excuse me for my english. I'm from Italy.