As for me, I have taken a 5 way bet as I do enough flying to get WP equivalent with each. Joined AA, SQ, DJ and Malaysian ( who may be a outside long shot) in this race.
All you're achieving by splitting five ways is spreading points all over the place. Furthermore, you'll have to earn the lower rates and move into the high rates of earn for each which is reducing yield. On top of this you aren't able to maximise your points earn from CC's and hotel stays. So in the end you'll get less. Once you have lounge access at most airports getting a double up is of very little use.
Anyway basically that this reaction shows is that you're not economically rational in the pure sense (and not many people are as people are emotional). As stated earlier, nothing (very little) has changed for WP (in this new announcement) and nothing has changed for other programs out there. But because SG's yield has improved you're looking to change. This actually doesn't make sense. From your perspective each transaction is the same as before but because someone else is getting more of a benefit compared to you you're going to make a different decision.
What i've stated above there is economics in second year uni. Most people who only did first year only don't quite understand the logic above though the underlying theory through out economics is the same. Sorry to take the highbrow approach here but you just don't get it. You seem to be a business person running or looking after a business, maybe you come from the sales or trade side and worked your way up but I feel this basic economic theory and understanding is important for you and your business. If you make business transactions emotionally and to take revenge at another business you will be losing money (or not earning as much as you could).
Pick the best program for you other there and put your business into it. If you want to diversify then pick one other airline. Do the maths, model it out and work out per flight who gets you the best return on points you an put back into your business including CC spend as I'm sure that's a major expense as well. Splitting five ways will hurt you but make you feel better because in your head you're getting back at QF who feel you aren't as important as the J flying WP's (which you aren't).
Also these travel costs are taking money straight from your EBIT. I suggest you do an analysis on your customers and only frequently visit the profitable ones and reduce the visits to the less profitable.
Wait a minute I think this is what QF did when they recalibrated their QF program last week...
In the end I'm not saying I'm more intelligent than you, just that I have a commerce degree and i suspect you may not. I'm sure you're excellent at what you do, but what you're about to do with your FF programs is going to hurt you not improve your position. Reconsider (and i'm not saying stick with QF)