Well, I think it's really not about supporting only one sim or several. I'm one of the 2000 who pre ordered BOS, but I'd support any number of convincing projects.
IL2 BOS happens to be in a place where I feel confident enough to support it by pre ordering it. With DCS WW2 1944 on the other hand, I see no re assuring signs that things will go any other way than they did with COD (they could go even worse, as Kickstarter pledges are NOT pre orders and RRG will have no obligation to give pledgers anything for their money). I have pledged for many projects on Kickstarter (45 projects to be precise!), sometimes projects undertaken by one or two guys only, and yet the DCS WW2 1944 project manages to be one of least detailed pitch I have ever seen there - this doesn't help at all. Given the way they presented the project, RRG can feel lucky that they will reach the initial goal. It's not that they "ruined my life", it's just that their previous project was very disappointing and heavily flawed, so now I'll just wait to see more concrete things before I get excited by this project.