Because it's not worth it.

When you create a game, a port, a remaster or a remake, you have to ask yourself how much money you can expect to win from it, and how much money you are gonna put in it.

A lot of people are spitting on this port because it's a pretty basic port, that it has some issues, and that Capcom has been really lazy about it.
But that's logical.
I mean, this is the fourth time these games got released in total. Even when they first launched, they were not very popular despite their qualities. So know, after the anniversary collection and the HD collection, we get another DMC collection.
Everyone that wanted to play those games have already played it, and most of those who still have it on the PS3 won't buy it again.

In other words, they don't expect to sell much about this re-release, at all.
Just look at the DMC HD steam sells after a day. 3000 units and 500 are playing at the same time? Oh yeah, it's only been a day but I don't think they are gonna sell 100k on steam, even though it's the only plateform that was really waiting for it.
There is thousands of times more people that buy each year their FIFA update.

That pretty much tells why it's just a basic port. They were not expecting much of it.
I don't even know if they are planing to make any profits on it.

Most people ( like 95% or so) prefer new games.
Porting old games is not worth it. Even more if the games were not very popular to begin with.

So why have they made this port? To please us?
Don't think so. The last time they ported this games was 2012, and the next year DmC: Devil May Cry was released.
So it seams pretty obvious to me.