The statement that the game will never leave early access is a huge, huge red flag for those already burned by Steam's ever-increasing mountain of shovelware.
I'm sure you are just meaning it will be hard for me get anyone interested in the game because of the EA tag, so forgive me if I look into this too deeply.
EA is can be a sketchy thing for sure, but I think at least part of the responsibility goes to the person who buys it. I research every game I buy. Or at least noticed that the one's I play for any meaningful length of time are the ones I researched. Every game is different, and there's the possibility that the devs are lying, but as far as space engineers is concerned, there is enough information out there to make an informed decision if the game is worth it or not.
Space Engineers has been in Early access for two years at this point in time. The game had received weekly patches on every Thursday since it's inception.
Adding new blocks, features, bugfixes to old bugs, new bugs, and design changes. A few weeks ago we had the 100th patch for the game, and more more recently, we had the 2nd anniversary of SE. There is a vast sea of video content, in addition to being popular and well known,
LastStandGamers has dozens of SE vidoes that break the 50K and 100K mark, Then there's
Sage,
CaptainShack, and a few spotlights with some of the Big wigs like the yogscast and nerdcubed. All, showing you what space engineers is capable of, both it's strengths and shortcomings, and how
it's evolved since it's birth. The devs have stated that there with be a point of official release where the core game design is finalized, (Ala KSP when it officially left EA), but will continue to work on it as long as they are able to do so, kinda like terraria in a way.
I can understand if someone is not satisfied/interested with Space Engineers, but I would not agree if someone said it was a scam. Like I said above, there's more than enough information from the devs themselves and third party sources to have let you known what you were getting into.
Also another issue I have with the Early Access tag is that it's too broad. Some games are put in EA to get some last moment for large scale playtesting in the polishing phase, while others like SE and Kerbal Space program were put in EA in the phase of the game were core features were still being designed and added, pretty much being being built from the ground up by it. Also some games like, Minecraft, Guns of Icarus, or Natural Selection 2, Any MOBA are dynamic in nature and have to be frequently patched to address balance and even design changes. I think some games would be better classified as perpetual development, rather than early access.