5BX isn't 'wacky'. It was designed by the RCAF to ensure airmen could remain in top physical condition without the need for fitness equipment.
Consistency is at the core of the program and it ramps up slowly to build good daily habits with deceptively easy exercises. Challenge comes quickly after those habits are in place.
I found it the perfect program while in the startup phase of my company. Taking an hour or two out mid-day to go to a gym was impossible during that time, but going into another room to exercise 11 minutes each day was no trouble at all.
Well, I guess what I mean by wacky is unusual, unique, outside of the norm, etc. It just seems like instead of just working out regardless of what the program is, people often times get jazzed up about some new exciting approach they hear about on the internet like 5BX or P90X or 300's kettle-ball training only to stop doing it after a few weeks because in the end it's just hard work like any other routine.