Ok I see where your coming from. To be fair, I'm not saying it doesn't look a little shady when outsiders see things like this. Sometimes you just have to be involved in a particular industry to really understand how things like this are handled. I really don't mean to come off as "Super Defense Force" either. What I'm saying is this sort off thing extends to many industries and I've worked in a few of them myself.
Many high-end professional careers involve people receiving 'gifts' many of which are not even material in nature. Take for example paying hundreds of dollars to fly people to their events, including accommodation.
Now what if a particular company would like to fly another company's Executives First Class instead of Economy? Is that unethical?
What if they would like their guests to stay in 5 Star Hotels? It maybe the case that's how that particular company treats their own executives? Is that unethical?
Have you ever heard of BDM's and do you know how much money can be spent lavishing both existing and potential clients in certain industries?
To be honest a tablet would be considered a very small gift in some of these other jobs. Now people in this thread making comparisons to Government Officials accepting gifts who are essentially; voted in and being paid by the populous to serve them are required to meet all sorts of regulations in regards to 'gifts' for the sake of transparency and integrity. Its a totally different situation.
Any field where being impartial as possible with products is a must; accepting "gifts" from people that are trying to sell you something is almost always a big nono, it is imperative that you remain as impartial as possible in relation to that companies advertisements and the game.
Companies that keep/still send out gifts are not doing it to be nice, they do it because they see a rate of return that makes it worth it. Also, comparing a media industry that lives off reviews and previews to any other non product review/preview/endorsement industry is being pretty ignorant of why it is different(advertisement and marketing work on everyone to some degree). As for the Thief argument that "well it got a 6/10", that argument would only work if 6/10 was the lowest it could have gone. Maybe the reviews would have been even more harsh and/or the scores even lower if there wasnt a perception of partnership/friendship or some other non product related reason for given them a, higher then you would otherwise, score(and/or you might have written harsher things). Gifts, travel events, press kits, and ect are forms of nonrational influence marketing advertisement and it has been proven, through studies, to have real influence on individuals.
Nobody is immune to these sort of things(gifts and advertisement in general), you are not immune to it, everyone just reacts different to different forms of advertisement, but it still effects you. And the fact that game companies still do press events(like being sent to nice area's and ect), press kits, gifts, oh and also hiring from said media field, along with other random things, infers them spending money on these sort of things still has a rate of return worth investing in. So everyone who actually chimes in and says "oh it doesn't matter" or "it doesn't effect me" are part of the problem and are either lying or ignorant to all the psychological reasoning behind these corporations "gifts".
As for the government being a totally different situations... In terms of positions sure, but the reasoning behind why you cant still is the same. Objectivity is, in part, lost. People who argue otherwise are probably the same people who think advertisement doesn't effect them.