Colonoscopy has only been around for a couple decades and obviously we will need more time to definitively conclude its benefits;
Actually it's been around for nearly a half century now. And rather than "definitively conclude its benefits" -- it is beginning to look like there are no benefits that are worth the ADDITIONAL collected attendant risks of this (truly invasive and oversold) procedure.
at this time, all published research points to colonoscopy as an effective method for preventing morbidity and mortality associated with colon cancer.
Alas, but another assertion which is simply NOT true.
No one is forcing you to get a colonoscopy
Alas, but the profession is ridiculously, even often abusively pushy about it.
even the research article in the first blog you posted showed that colorectal cancer screening reduced associated mortality by over 50%.
And? First of all that statistic is of dubious merit (again things like 5 year survival, and lead-time bias, etc) -- and secondly, while that 50% reduction SOUNDS huge, the overall risk is relatively low in any case (and chiefly occurs LATE in life, so the "overall lifetime risk" statistic that is often cited is needlessly misleading; i.e. it's "fear-mongering"); and the risks (including premature death) from colonoscopy (especially multiple colonoscopies) are nearly as high, and for younger people are actually higher than the risk from the cancer (so we have a case where the supposed "treatment/cure" is WORSE than the "disease".)
The CDC and the USPSTF recommend colorectal cancer screening for a reason.
But not necessarily a "colonoscopy".
The guidelines are in fact old & outdated -- and yet even the "current" {finalized/published circa 2008} guidelines are a slow/steady "backpedaling" from the prior screening & colonoscopy recommendation.
They DO continue to recommend screening -- but ONLY for people in age range 55 ~ 75 -- and then staying rather silent/ambivalent regarding the TYPE of screening (no longer actually recommending colonoscopy). They continue to recommend screening chiefly because the "early detection" fad/meme has not yet died out... and they have not yet updated/integrated into the guidelines the results of more recent long term studies (which, as with so many other cancer screening protocols, looks like it will prove the "benefit" {if any} to be trivial, and probably rather dubious).
And of course changing the guidelines would (will) be a HUGE blow to the incomes of a substantial specialty, one which is quite influential -- so in addition to other similar (less than transparent) motives there is some effort to "cushion the blow" upon the profession.
See also: Colonoscopy: A Gold Standard to Refuse