Annoying parameters and exceptions

There are some small annoying discrepancies in the .net framework. Some are real, and some are just due to my lack of understanding of the genious of the designers who made it this way.

Today my annoyance was created by the IDbCommand object's Parameters collection. Whilst both the OleDbCommand.Parameters.Add() and SqlCommand.Parameters.Add() returns the parameter added the IDbCommand.Parameters.Add() doesn't return an IDbParameter but an int indicating the index. Why is this annoying? Simply because it makes it impossible to write a parameter addition on one line like this:

IDbCommandObject.Paremeters.Add(new IDbParameter("@param", DbType.Int64)).Value = myLong;

Another question mark is why SqlException and OleDbException have no common baseclass or interface other than System.SystemException. One might think that System.Data.DataException catches these but that one is just for plain ADO.NET exceptions, not providerexceptions.

If there is a good reason for these things I'll be glad to add this to the pile of genious .net framework design choices.