Two questions there

Diabetes destroys blood vessels which effects circulation. If circulation is hampered then the immune cells that do the actual healing can't get where they need to be in the quantity needed so you heal slowly or not all if the vascular damage is advance

The latter is what results in lower limb amputations - infections in the feet or lower legs can't be fought and gangrene can set in

The "root cause" of 95% of Type 2 cases is the (patient) treated their body badly and damaged their metabolism

You don't "catch" Type 2

Some people - about 8 out 10 have better "genetics" then Type 2's

They can carry a "few or many" extra pounds, those that are diagnosed Type 2 "can not" - if you let yourself get overweight that is one of the biggest factors in triggering onset

To a lesser degree eating a "crappy diet" contributes as does lack of exercise

Those are the three big "root causes" and those are directly the result of lifestyle choices that (we) made

And once you have "broken" your metabolism, the pancreas tries to overcome you treating yourself poorly and starts working way harder than it was ever meant to

By the time you are actually diagnosed with Type 2 you may have already lost 70% of the functional ability to produce your own insulin - 6 years is about as long as you can abuse the pancreas before the damage can not be reversed "at all" - so if you "suspect" you may have had diabetes for a few years before confirmation, that 6 year clock started "back when" which leaves many with "little time to get their crap together" and 7 out of 10 newly diagnosed "don't believe they actually have a problem" so continue making excuses or dragging their feet

If you get "immediate normal control" upon diagnosis you can "give the pancreas a break" and it can regenerate it's ability "somewhat" but not completely - burned out is burned out

And if you continue to carry that extra weight, which increases your insulin resistance, you will never give the pancreas a break

Upon diagnosis, within a year or two if everyone diagnosed got to normal weight, started eating low carb and started exercising (and walking at work is not exercise) 80% would have the ability to at least achieve non-diabetic blood sugar averages

That wouldn't "fix them" but it would alleviate diabetic complications

So being brutally honest here - if about 95% of Type 2's want to know the "root cause of why I got it" they simply need look in the mirror - because that is the answer

Now if instead the question is "why did my genetics suck compared to the slob that lives next door and is fine being 200 pounds overweight and eating pizza chased with beer for every meal", that is a totally different question that has nothing to do with diabetes

Wow!