I think it's really a bit hard to compare making the two. In terms or being right out of the box process, wine is definitely easier to make. Add juice, add water, some other stuff and let it sit. Beer is kind of the same; add water, boil, cool, aerate, pitch yeast. Both processes in my opinion make an "ok" product assuming they are both given an equal amount of respective attention during the fermenting process. Malt extract beer is better than $75 box wine kit. The real question is when you take it to the advanced level i.e. AG brewing v. crushing/pressing your own wine. I'll leave out growing the grapes because in my opinion that's equivalent to growing and malting your own barely.
That being said, as someone who has done both wine and beer, I believe it is far easier to make a quality beer along the commercial lines than it is wine. The reason being, in my opinion, is that we as brewers pretty much have the same access to raw materials as the pros do. After visiting several wineries in Sonoma and listening to them talk about the attention to detail payed to picking and crushing the grapes on a certain day, I cannot say that home wine makers have that same access. Therefore, it really is difficult to make the same caliber of wine as comparable to beer. And since grapes cannot be grown everywhere in the US how can one make a comparable wine. In addition, as a wine maker you need a ton of space and need to pay very specific attention to the chemistry of your grapes and understand how to make the proper adjustment if something is wrong. Or else you've spent all that time and effort crushing and pressing hundreds of dollars of grapes to make a year's worth of so-so wine. As brewers, most of the time we had no idea our water chemistry was wrong until someone brought it to our attention. All the while we were still making commercial quality beer.