The internet has reacted in different ways to remasters. What I'm saying isn't just true for VGC but all gaming sites.

God Of War III: Remastered: "What the hell Sony? Why you ripping us off? Won't buy it. This sucks man"

Tearaway Unfolded: "Its okay I guess, but I would have liked a new game instead"

Gears Of War: Ultimate Edition: "Microsoft you're the best! Day one buy"

All these games are remasters of just one game, all of them were very well recieved, but the reactions are vastly different to each one.

Tearaway Unfolded isn't a remaster

Funnily enough I have the original PC copy of Gears of War from way back. Could already play the original in 1080p 60fps :^)

But hey 4k addition is nice.

It's like asking why people praise LoZ and Majora's Mask on the 3DS despite the fact that they are remasters (yes, remaster, not remake, they got nothing truly notable but a fresh coat of paint), yet they bashed basically every HD collection of PS2 games that came out on PS3 and Vita last gen. People are simply inconsistent.

It really should be clarified that Tearaway is not a remaster, but a totally new game, as the second poster mentioned. This is a Tearaway game built from the ground up with the PS4 in mind. If you doubt that, just watch the live coverage video you can find on Playstation's youtube page. At no point do they refer to the Vita version except when referencing their thinking on improving their original ideas to make an even more unique PS4 experience.

How is Upgraded graphics and bonus levels not a remaster ? 

Bonus levels don't make it a remake IMO, nor a sequel.

I think you should remove Tearaway from the OP, as it's not a remaster.

The answer is obvious: bias. People who don't want to admit their bias, though, will come up with an excuse.
e.g. "It's not needed". "But that came out recently", etc.

I don't see the huge value in remaster titles, unless they're quite old and the tech has made them age badly. Examples of good remasters are the old D&D RPG's that have been overhauled lately. A remaster of late 360 and PS3 games for PS4 and One are just a bit silly in my opinion.
Remakes are an entirely different matter though, that actually means changing up the core elements while sticking to the same general concept.

It isn't just upgraded graphics. It's a retelling, which is basically to say it's a remake. It's being remade with the PS4 in mind. That means levels will likely progress entirely differently, will be larger, and will be changed to deal with PS4 specific features. A remaster is just slapping a fresh coat of paint on exactly the same game underneath, which would legitimately be impossible going from a Vita specific title using all of the Vita hardware to full control via a PS4 controller. I doubt it was at all easy moving Tearaway to the PS4, and it almost feels like an insult to the developers to classify it along the same lines as the PS2 HD remaster collections and the like.

It's a curious thing. While the Rare games remaster is a godsend for everyone, the God of War collection for the PS3 was something irrelevant and a signal that Sony's consoles have become a haven for remasters. It's this kind of double standards I really dislike from people. I honestly don't see something bad on remasters, unless I see five of them announced and released in a short period of time; now that's worrying. But I guess this criticism will never stop.