Absolutely- in fact, it's to be expected. This is why it's very important to learn how to address people whose work you're proposing to change with as much respect as possible. Being able to take a different perspective and see someone else's point of view goes a long way in this case.
From our perspective, we know our idea will work better than what already exists. From their perspective, we are uninvited interlopers who, by critiquing their work, are telling them they have no talent. This may sound extreme but if you look at the situation from the different points of view, this is what it boils down to.
Often, it's also a matter of demonstrating how something will work- essentially proving the efficacy of the new idea and then, suggesting everyone live with it for a little while.