Maybe it might seem easier in the short term to some, but as a semi-experienced programmer I am going to have to insist that a lot of the time 'special cases' like that just end up being really annoying to deal with. Because you can't just 'simply' introduce stats like that. You have to jam them into formulas in awkward ways to get that to work, especially if you have a lot of them. Soon you will be left with formulas that are total messes of special cases and extra stats that are only ever used in a few places. And of course now when you want to re-balance something you are going to have to find all those special cases and change them too. Not saying this isn't ever done, but this is bad programming 101. People who do this are terrible coders and will make a ton more work for themselves sorting out their own mess in the long run. Trust me.
You know the thing is, we both agree this kind of thing is bad. Only you think it's because it's lazy, and I think it's because it's just stupid. Anyway being lazy is not necessarily a bad thing. I admire constructive laziness. Actually finding ways to save oneself the bother of doing work is only a good thing, as long as it's done properly. This is not that. This is just not knowing what you are doing and trying to solve the problem in the most brute force way possible. And that probably is a form of intellectual laziness of a sort, in the end brute forcing a problem is pretty much always going to be the least efficient way of dealing with it.
I guess what I am saying is, saying devs do this because they are lazy is an insult to lazy devs everywhere. And as an incredibly lazy dev, I take offence. :P