I think it is a mistake, often made, to assume that any and all "mods" make things better.
Based on this quote, I agree 100% with what macrojack is trying to say. Upgrades do not always result in improvements and sometimes can take one in the opposite direction of where they want to be with any given product.
As I have mentioned in the past, if one does not like a product from the beginning, upgrades/modifications are not going to turn that product into something it's not. At this point, it's time to look for a different product. Putting more money into it with unjustifiable expectations is simply throwing money away.
I do believe, however, that there are situations where upgrades / modifications can enhance the performance of a product that someone already enjoys and realizing it potentially has more to offer. Basically bringing more of it's potential to the surface.