Nope, its weapons grade baloney. Shaft will deflect with or without soft tips.
Probably good reasons to use a soft tip. I personally can't think of any, but maybe someone else can? You get more spin? NOPE. You get more control? Well, personally I like to feel my tip hitting the ball, rather than trying to gauge a feather bouncing off a marshmellow. Can you jump full cue with it? NOPE, at least not half as well as with something harder. Can you break with a soft tip? You really shouldn't if you want to keep it soft. Does the tip wear faster? Hell yes. Most players who play with soft tips take the tip down significantly as well, to get some measure of feeling with what the hell is going on with the cueball. You need that when you have a wad of pillow stuffing on the ferrule. Guess what happens when you take down the tip like that? The tip starts out lower, and now it hardens up faster and wears out faster. Once it's hard, it starts playing better, because duh. Then the cycle continues, the player buys a new soft tip, which plays like crap until it hardens up again.
The only real reason I've come up with is trying to take speed off the cueball. IMO it doesn't work great for that either. Stroke work will do that job a lot better. There are also a couple of specialty shots, that come up more often in carom than pool, where I will admit the soft tip is preferable. One is the "nip-draw". There are a couple of others, but again, they are rare and IMO not worth it.
