Have we even confirmed that tipping raises style? Simply beating the restaurants increases style on its own.
Well, personally I only did one restaurant battle early on and never really did the pokeball method of increasing style (I only bought about 10 balls and got bored with it as it was not seemingly helping.) I tipped the living daylights out of everybody though (including the taxi driver.) That's what ultimately maxed out my style and unlocked hatch power.
Using the Taxi and the like already increases style. Tipping them means nothing to them as proof raising style because of that. Presumably all of the other things that you use tipping for also were in the same boat.
Actually, nobody really knows all of the mechanics that truly increases style either. Nintendo hasn't announced it and I haven't seen references to the released guides that state what does either.
Bottom line though is that nobody really knows what tipping does or all of the style raising mechanics. All we have are anecdotal evidence at this point. Nobody has data mined the game to find out for certain.
Regardless of all of this, tipping most likely does have some effect (why else would they put it in.)
Q: What is the functionality of the Gem in the Diablo II Battle.net Chat room?
A: While we cannot reveal the purpose or function of the Gem in the Diablo II Battle.net Chat room, we can say that it is working correctly and has more than exceeded our expectations. Also, Blizzard employees cannot confirm or deny any rumors regarding this Gem.
Tipping is 'working as intended'. You want to know what it does? Nothing. it doesn't do anything. if it actually does something the effect is so miniscule that it doesn't matter.
What's really baffling is you don't believe buying luxury balls increases style, but you believe tipping actually does something when you don't have any proof of that either.
Why does it need to actually do anything to exist? It's a red herring, it's designed to make players like you go 'this is increasing my rate of shinies!' and keep you guessing and leading on even simpler people with all manner of radical theories.
I didn't say that I didn't believe that buying poke balls increased style. I believe it actually does as others have had success with it. I bought a few, and got bored when with it. I just didn't have the patience to sit there and buy 99 balls one ball at a time to get it to go up some. Ultimately, I got there, but I did it a different way. I never said that my way was better, that is you implying that.
My final point is still valid though. I do not know what tipping does. You do not know what tipping does. Neither one of us knows the true mechanics of style increase. All we have right now are anecdotal reports by several camps. There are the poke ball buying camps. There are the tipping camps. Neither one may be wrong. Neither one may be right. For all we know, it all comes down to gameplay time. The only people that know right now are not talking. Without being able to data mine game at this time, we will not know until some guide is released or one of the developers tell us.