Personally I am a tad dubious about this. Increasing stats does not just make the players more powerful, it also shifts the balance around a bit. It's subtle, so I can't say it would necessarily affect the game significantly one way or another, but it's something to be aware of.
For example, I could make a Monk who puts his highest stat in Str and still has a good Dex, Con and Wis. I could be looking at a +8-10 or so to AC from Dex and Wis combined. That's as good as a Fighter in Full Plate with a +1 Dex. Suddenly the fragile Monk is looking pretty solid, given he still has as good a Str as the Fighter too.
Everyone's saves are going to be a bit higher because their secondary stats will all be a bit better. In fact, they'll be getting bonuses to everything and penalties to little or nothing.
Now, in some ways these may be good alterations. MAD characters can come out a bit more, and the bonus from stats round out some of the differences between high HP and low HP, high saves and low saves, etc. I means that Fighters can get Combat Expertise without harming themselves too much, and so on. However, it favours some characters over others so I'm not sure it's a thing which can easily be accounted for.