Does it really matter if they care about artists or not in this case? In order for them to get good publicity to the audience of Penny Arcade, they have to cater to artists. (assuming you aren't cynical enough to believe that Gabe is just a shill for Microsoft, which he likely is not) If Surface 4 comes out and they don't fix any of the issues Gabe has mentioned, and they send him one to review, he'll point out that things were not fixed, and they were obviously not listening. I think at that point it would be valid to say they don't care, but the way things are described, it does sound like they're trying to improve the product, at least for the specific niche Gabe occupies.
Remember "I'm a Mac / I'm a PC?" The loyalty that Apple built up among creative professionals has under-girded their entire brand. If you were Microsoft, and you saw a chance to knock some of those people loose, wouldn't you work like hell to make that happen?
This would also be an example of MS improving its touch in terms of attempting to persuade people about Surface. Rather than just repeating over and over about how great [tabletX] is and how a celebrity they've paid to endorse it just loves it (see HP's disastrous TV campaigns for their tablets), they're letting an influential guy use it, review it, and criticize it publicly. The critical bits are what make it more effective as commercial messaging for MS' particular purposes at this moment.
If Gabe were shilling they would pay him directly to shill and it would be marked as an ad (which PA has done many times before for many companies). In this case, that's probably not happening.
He is getting(and keeping) free hardware, I would consider that getting paid. He clearly states he got the item under review for free and once he complained about the performance they said they would ship him a high performance model for free as well. They used to give away any such free loot specifically to avoid the shilling moral hazard.
