Jewel, I disagree.
Acceleration, especially radical acceleration, obviously involves tradeoffs. It creates an age discrepancy with classmates in order to approximate an appropriate academic level.
However, I think it's going overboard to be so afraid of a single skip in kindergarten based on a parade of horribles from middle school. A PG child's educational options may change so drastically by normal middle school age (minus one) that these concerns are completely inapplicable anyway. A PG child may be taking college classes at that point. It's not valid to deny someone academic advancement at the proper pace and level based on concerns over sexting; such concerns are irrelevant in the face of such an academic mismatch. The thing to do is instead be creative in finding the best fit possible, while addressing social and safety concerns as well as possible.
Social and physical maturity are certainly important to consider, but concerns in kindergarten over a one-year mismatch of these factors in middle school are in my opinion never a reason not to skip a kindergartner. Before skipping a kindergartner, nobody is really going to undertake a months-long investigation involving interviews with middle-school boys of friends; interviews with lunchroom staff and custodians; interviews with gym teachers and coaches, asking to view locker rooms, walking the halls with special attention to watching boys, and seeking out parents of boys; reading months of middle school status updates, Facebook posts and blogs; an analysis of how young men are depicted in popular culture; and possibly repeating at the high school level. In fact, upon requesting access to do such things, serious concerns would probably be raised about one's true intentions, especially with a stated reason about a kindergartner.
Grade skips can work quite well, and this is supported by research. We don't need to be afraid of negative effects many years away when skipping a kindergartner. Instead, what's called for is a rational assessment of each proposed skip on a case-by-case basis. Reading up on on experts' opinions and research findings can help (see Hoagies, A Nation Deceived, etc.).
This is very well said. And the path we will take when I anticipate we will be considering a skip for dd5 in the future.