So even without the glitch it gets stronger? Sorry I have no idea, i see stuff about it all over this board but I've never actually used it, ever.
the glitch is the fact that you can stack the effect on other weapons.
The effect itself is not a glitch.
Multiple copies of the effect is part of the glitch, though. It isn't "stacking" the effect to other weapons, it is "adding multiple effect-chances". Over time this adds up to the point where the Evil Smasher can cause a game-crash. And also to the point where it can make any gun do 2 million base-damage, though that is also adding hundreds of ammo to the clip at that point.
Thus, the glitch is that the effect gets copied/added-to. That's why it affects other weapons.
I guess the concept was that you could get a powered-up reload, and on the off-chance you recieved a powered-up reload after that, it would raise it to a higher level of damage (and keep doing so on the "intended to be low" chance it kept doing it).
The problem is you could cancel the reload and it would apply the damage boost... as well as "infect" the weapon slot you were switching to.
Kind of all-around buggy on so many levels, but in a way that's good if you want to exploit.
If they want to fix it, they'd first have to make sure the boost only applies after the weapon has actually reloaded. That might fix the problem of exploiting the stacks, since cancel basically lets you keep reloading until you get the effect (it appears that boosting the weapon to higher levels also increases the odds of getting a more powerful reload, which is why eventually you'll always get a boosted reload).