No, this is not true at all. In practice every program is typed. There is no useful function that is fully general, so in practice there are limits on the types

No, this is not true at all. In practice every program is typed. There is no useful function that is fully general, so in practice there are limits on the types and the values of the inputs. All dynamic typing gets you is that you can ignore this fact, and then hit it head on when you make a mistake. It is possible to give programs that are truly dynamically typed, but they are not "real" programs. What can you do to a variable with zero information on what it contains ? Not much : return it, pass it around, ... that's about it. The real complaints are mostly about two things 1) it's hard to know what type an input parameter should be, so I just don't. This is just not a valid complaint. But type inference helps a lot here. Generic programming catches the other usecases. 2) many languages make it really hard to correctly specify types. This is a language flaw. Dynamic typing can be an improvement over C code, but not over Haskell code. Other languages are somewhere in between. Sometime, it's another flaw that may exist : the standard libraries are not correctly thought out to have a good algebraic structure (e.g. correct IS-A relationships for all number types, and the ability to generalize over them) These complaints basically boil down to people having constructed wrong type systems. It's a flaw in many, many languages. Python and Haskell are the only ones I know to get it close to right. 3) You want to eval() in your program (or, for example, read in arbitrary json). If you're doing this, you're doing something wrong. Even if you do manage to isolate things correctly (history says you are unlikely to get this right), you're open to trivial DDOSing.