Tough to fault the logic in this brief discussion -- despite the purist's urge to rail against it.
A critical aspect to taking an existing idea and making it better, more viable, more commercial, more available, etc. is the benefits to the industry at large and the markets served.
I can think or scores of "Imitation Innovations" that have provided endless benefits -- ranging from more jobs to better quality of life: Wang word processors and computers evolved PCs and Apples; Magellan evolved Windows and Mac OS. And don't get me started on biotech and pharma developments.
In Cleantech, early evolution is still happening in real time, before our very eyes: the evolution of solar panels to today's photovoltaic cells; LED lighting; Syngas; algal fuel processes -- even food packaging.
And have you tried to secure funding for a truly innovative product/ service/business model during the past four years ... !? Let's just say, "Imitation Innovations" are far more appealing to the overwhelming number of risk-averse (i.e., zero risk) funding sources out there.
I guess my purist side is at peace with this.