I think the OP on that thread was misunderstood. He stated that he didn't get his pilot slot, but "still wanted to fly". My understanding, based on the rest of his initial post, was that he wanted to continue his pursuit of a pilot slot while serving in his assigned AFSC.
The advice he received was to pursue a navigator slot, and chase his pilot dreams after the fact. When I was a cadet, nav slots were even MORE competitive than pilot slots (there are typically less of them available).
If you want to be a pilot, put that on your dream sheet. If you're categorized as something other than pilot prior to commissioning, then tackle that dummy when you come to it. You can always re-apply for pilot training once you are on active duty. There are policies that govern that, but don't worry about it until/unless you have to.
depends on the year... my fiscal year in ROTC they were actually begging people that hadn't gone pilot or nav to take the extra nav slots because they didnt have enough people apply to do it.
This year, out of 20 commissionees, we had 8-9 rated slots. We had 3 pilots, the rest went Nav with no ABM selections. I'd say that it was less competitive this year, but if they have fewer nav slots than pilot slots it would be more competitive. That's the process as I understand it anyway.