Everyone, let's try to keep the comparisons on an "even keel" 
Some O-gaugers only buy one company's products and/or command system...nothing wrong with that...probably simpler to learn and operate via one system.
While I pretty much buy only O-scale trains from Lionel and MTH, I am a bona-fide toy train guy I am so glad that the folks at Lionel went against the tide and made O-scale fantasy trains in the Polar Express, Milwaukee Road, Union Pacific, and other road-names with the Legacy system.
By the same token, I am grateful that the folks at MTH made unique scale European steamers and American steam and diesel-electric engines with DCS.
Undoubtedly, there's been a lot of money spent on tools and dyes, and perhaps, if demand is strong enough in future years, someone will re-issue all of the wonderful variety of models with one command system. Until then, we can hunt down older versions and/or lament on the models we parted with 
