Why are .Net UIs slower than C++ or classic VB?

I've noticed (for quite some time now) that .Net UIs are not as responsive
(see Franklin Covey's PlanPlus for Windows XP or Symantec's .Net Norton
Antivirus or even the .Net version of Paint done by Washington University vs
good old Paint UIs for examples).

They are also not as professional looking as the older applications and the
reaction times of the UIs is not professional looking at all.

Why do you think this is? Is it bad programming or is there something else
going on here?


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