Well in my opinion, I've seen a lot of others who are happy about this (including me!) so I'm curious as to think why you're alone, even with all the negative threads and posts.
My guess is some people out there expected some free cars and tracks, especially the older ones, or something.
I thought there was three things that most should at least appreciate the slightest bit:
1. Mid-race saves - This is only the most voted feature...
2. Spa - This is only one of the most requested tracks...
3. Physics/A.I - This is only what the game mostly revolves on...
Basically, those who are disappointed probably wanted a bunch of new tracks, events, and cars. To be fair, apart from Spa, there isn't really much to look forward to considering the cars are just RM versions, and an upgraded X2011. I can see how a lot would be disappointed by it. Personally, I think the RM cars are hot, hot, hot.
Is it confirmed that there is more DLC after the first one? I'm assuming there is. If not, then I'd be let down to be honest. I'm happy with the Spec 2.0 for sure, but I at least wanted a lot of GT4's track to return. It would seal the deal for me. After that, I just want PD to focus on GT6. It would seem a lot of us need fresh new, A-spec experience.