You use LaTeX
instead of a WYSIWYG word processing program because they can’t cope with the high quality required for publication. But your nice professional looking documents can be ruined because you insert the wrong type of figures. Bitmap figures are easily pixelated because the actual size is not always known beforehand. Exporting figures as PDF to be included sounds like a good idea but you’ll quickly notice the problem with the text (e.g. axis label and ticks,…) which needs to be rendered by Latex to get the correct font and size.
Hard-core Tex users can find the answer to this problem in Tikz or Pgfplot. Of course figures generated at this level is as good as it gets. I use Tikz picture quite frequently for text-heavy diagrams and simple plots. However, if the figure is moderately complicated or if it’s bound to precise data, then generating figures this way quickly becomes unmanageable.