...snip...
Simply because one supports the status quo does not mean that one "assumes" that the status quo is best. It seems to me that you are starting from the position that the status quo is not best, therefore the only POSSIBLE reason someone might support is if they're being irrational. So you are the one not being skeptical. I could just as easily say:
Your restatement doesn't work because it doesn't arise from the principles of liberalism whilst mine did arise from the principles of conservatism.
Liberal principles do not lead to an argument that "change is good" as a reason for change but conservative principles can lead to an argument that "tradition" is a reason for not changing. In other words "Because we have always done it this way" is a perfectly good conservative argument for not changing something, there is no liberal counterpart of "Because it is a change" as a reason for doing something.