to cancel the fans' letters column IMO is a serious disrespect and lack of consideration to the readership.
(worse, without any previous announcement or clarification)
Mind you, I'm of the opinion Hudlin's been pretty damn disrespectful to readers already, but I fail to how cancelling the letters page is disrespectful in any real way.
Readers thee days have plenty of ways to interact with writers and editors these days. Combined with lower sales (across the board and Panther inparticular) it seems good business sense to me to can the page.
In fact, it's something you should welcome. As it seems you have complaints, writing a letter will have that much more impact as there will likely be fewer letters sent to Marvel overall (though that greater impact would probably be from .02 to .2%).