Well GT is better in every quantifiable aspect of a racing game, more cars, more tracks, both of wich are more detailed and look closer to reality, physic is closer to reality too as both claim to be simulations, graphics are closer to reality too, shadows, ambient lights, reflections, color saturation. All those things wich can be observed objectively are part of the reason a majority of people will subjectively prefer GT over Forza, it make for a more appealing and enjoyable experience. So GT is both subjectively and objectively a better game than Forza so far.
By the way, when you ask "What has the measurement used by the corporate world has to do with the subjective perception of the consumer?" Answer: it has everything to do with it, the more people like it the more sales, sales represent the subjective appreciation of a product, that include the actual product itself and the branding. What it has nothing to do with, is its objective quality, even though it plays a major part in the public perception and appreciation.
I wasn't trying to debate the quality, the objective or subjective one for that matter, just saying sales are only an indicator of popularity and not necessarily ( although perhaps
one of the indicators which
may suggest it ) a guarantee of quality.
If quantity automatically equals quality, which it doesn't in my book, then you could just blindly go for every bestseller ( given that it interests you ).
Ofcourse certain elements which make for a quality product can be objectively established by measuring objective criteria ( graphics for example ) although even if those elements are superior over another game that still doesn't automatically make it a better quality game overall ( just one or several aspects ) as a good game ( or good product ) is more than the sum of its parts and the overall quality is subjectively perceived and judged.
I didn't say sales aren't important ( ofcourse they are ) but when a poor quality game has good sales due to hype, etc. it doesn't become a good quality game all of a sudden.
You then perhaps have to take all those games which are resold or traded in after release into the equation too or how many people still play it after a certain amount of time, etc.
The quality of a game, being an entertainment product, is highly dependant on subjective appreciation of the individual player.
If a large or small group of customers perceive it as a high quality game ( no matter whether objectively they are wrong or right ) and there's some sort of consensus that it's a quality product ( again hardly objective ) then the total amount of sales is largely irrelevant to those customers, it only is important to secure a future iteration or support of that product for them perhaps.
The sales are important to the developer and publisher and acts as an indicator for them whether they're on the right track or direction perhaps.
The saying 'never change a winning formula' could apply here and therefore sales ofcourse have an impact on the content ( and quality ) of the game.
Which isn't the same as saying it gets better due to it though.