There's some merit to your point, but unfortunately it's not entirely correct. ALL crops on which pesticides are used retain some amount of residue in the portion we eat, but the amount does vary between crops in a manner that's partly related to the type of crop and what portions of it we eat, etc.
In any case, it's been tested and proven that pesticide residues are present in the food that ultimately makes it to the supermarket. For further info:
http://en.wikipedia.org/wiki/Pesticide_residue
The other significant issue I'd like to touch on is that not all pesticides are applied externally-
Source:
http://en.wikipedia.org/wiki/Pesticide
Some forms of systemic pesticides are applied to the seeds and remain part of the plant through its entire life without need for further application. Yum.