It's not bonus levels, it's different content altogether

They are not just bonus levels, It's a retelling. Which makes it a director's cut. Also at a better resolution and frame rate. Not a remake but better than a remaster. Then if the game has been rewritten and not ported and modified (I don't know)  it isn't a remaster at all.

Still to answer the orginal queston.. All remasters are good. They improve the experience and no one is forcing us to buy any. There are plenty of games I missed on PS3 that I may buy remastered on PS4.

99% of the time ''remasters'' are money grabbing schemes from the likes of capcom, konami and Sony.

When MS does a remaster, they go to town with it. With Halo Combat Evolved, Master Chief Collection and Gears Ultimate, they are impeccably reskinned to look and play inline with the games you see today.

Some of them do make sense. In the case of something like the Last of US, lots of people came to the PS4 without having a PS3. GTA V is kind of a delayed port...

Remakes versus remasters versus delayed ports versus HD versions

I guess they are all slightly different, but they are going a bit over the top in some cases I feel. FFX triggers a much better reaction for me, because it's a 10 old remaster instead of God of War III's 3-4 year gap (can't remember). Gears 1 is probably just old enough

I do also feel that some of these remasters are partially to help the studios learn more about coding on these new platforms and give them time to finish their games while keeping fans happy. Uncharted 4 (with the Last of Us PS4 to learn about the PS4 engine) and Gears 4 (with 1 as the test bed)

Different people want different games to be remastered.
Personally I'd like Nier to get a PS4 port.

To be fair to The Last of Us, the PS4 version was the version of the game they wanted to make, and it's undeniably the definitive way to experience The Last of Us. You may be right about the reason for why it exists, but at the same time, I almost feel like the PS3 version was a downport from their initial expectations that were able to finally be met with the PS4 hardware. With most remasters, that isn't the case. The remasters from last gen are largely unnecessary, especially ones dealing in non-exclusive content. Remasters of multiplat content, although convenient for some, is ridiculously unnecessary. I mean, the Borderlands Handsome Collection for example was a total kick in the balls to anybody that bought The Pre-Sequel at even sale prices prior to the collection's announcement and release.

Because TLOU: Remaster wasn't well made ?

While Halo: CE ran at 20-25 fps and the MCC doesn't run as well as promised (Halo 4 ~50fps and Halo CE still not 60fps for example ), with a broken matchmaking that is still not entirely fixed, more than 6 months after release ? 

Well God of War III is a port upgraded to 1080p 60fps. Gears Ultimate Edition is made from the ground up 1080p 60fps with a new multiplayer and 2 more hours that Xbox 360 owners didn't have. Both at 39.99 which is the better value?

It's already obvious that the discussion in this thread isn't going to go anywhere productive, and the OT itself is built upon a straw man. Locking.