While I agree with you, I do have some arguments,
**note is not suppose to make anyone upset, or start a riot, just some of my ideas, write or wrong**
**Also I wanted to apologize in advanced, sorry if this is off topic**
First off the reason that they keep pushing out more DLC is that they need to keep money flowing into the company to keep it afloat. If they would just stop all new development and focus on old products they could lose or not possibly gain any revenue, RSC isn't like EA railworks is their only source of revenue. I also have a feeling that they are updating everything and then releasing one big patch/upgrade to the DLC, especially since everything that has been upgraded has been from mainly 3rd party developers (exceptions to this are the NEC), but that is my own personal opinion and I have no sources to back it up.
Also to note about performance issues, from what I have heard from a newsletters and other sources they are working on patches to fix some of the FPS issues, especially with multiple core processors. Also with the Donner pass the first update was released, but currently they are working on another patch to fix some of the bigger issues, such as with the track.
I know people are frustrated with how things have been going lately, but we can either deal with what we have, or just leave the franchise all together, which for me is not an option. I love the franchise, even with its quirks, and I have a lot of money invested in it. The other thing we could do is really push the question as what is going on with the previous DLC, so at least we have an idea of what is going on, instead of being in the dark. As a community we got RSC to recognize the problems with DP, if we try again, we may get some answers on the DLC.
/End Rant, I'll step off the soapbox........
“I find that the harder I work, the more luck I seem to have.” - Thomas Jefferson