Whether you do or don't use exceptions, it's far from a bad idea for objects to always check their internal consistency on entry from external callers. As for dealing with errors in clean up, remind me again how exceptions improves on that? Would you throw an error from a destructor?
Also, you seem to be suffering from some kind of binary thinking - that people are either for or against something - and projecting that onto others. I have not at any stage expressed an opinion on whether exceptions should be avoided or not.