Environmentalism is often just a stated preference. Like humans shouldn't disturb some thing.
So it isn't necessarily the case that you need to be more knowledgeable to challenge them. Availability of inexpensive energy without burning coal is another preference.
I certainly have reached the point where I think popular environmentalism is waaaaay too focused on static conservation.
That's a generic view which I might actually be inclined to agree with you on. I'm personally skeptical of the current climate change politics, for example.
But OP made a more specific claim about solar arrays in the desert. Seems like we should be able to debate that on its merits.
That alternative to putting them in the desert is putting them in some non-desert area or putting them nowhere. If these people are objecting to putting them in a desert, they'll object to putting them in a non-desert area too.
Making better use og roof-tops generally is a win as far as environmentalists are concerned; NIMBYs/BANANAs may complain however.
Not that I see any intrinsic beauty in concrete titles or roofing felt. Even clay tiles and slates I suspect are just something we have gotten used to.
In all cases they are a financial and embodied energy and financial cost as-is, and PV can turn them into something positive.
Ignorant people look at a desert and see lifeless desolation. When they educate themselves they come to see the desert as an very active environment with limited resources, and cut-throat competition for same, that makes human impact more pronounced. Better to put solar panels over scrubland or even farmland than into deserts.
So it isn't necessarily the case that you need to be more knowledgeable to challenge them. Availability of inexpensive energy without burning coal is another preference.
I certainly have reached the point where I think popular environmentalism is waaaaay too focused on static conservation.