Just started a new career yesterday after a LONG break. Pretty basic rockets survive reentry pretty easily, especially if you put on some heat shields and caps. These parts might not survive the reentry, but all my kerbals and science did.
There seems to be a bug with the heat shields – they don't have mass, so with some capsules the centre of mass is too high and they flip during re-entry. This kills the crew.
But otherwise, yeah, you're not supposed to bring back more than crew and the experiment results, unless you build a space plane.