There are plenty of valid concerns and complaints about Amazon (I'll list some of mine below), but I don't see why you're blaming them for electronics recycling and lifetimes, or "Walmartification". Amazon has done a pretty good job of being an all-in-one place to shop online and having very low prices overall.
For cellphone replacement cycles, I have absolutely no idea where you get the idea that Amazon has anything to do with this. AFAIK, most Americans still "buy" cellphones at cellphone stores run by the big 4. You can blame them for the 2-year subsidization scheme. And phones are lasting longer now. I have a 3-year-old Galaxy S4 that works great. For a while, there were huge changes in the hardware, but it's plateauing now.
For laptop replacement cycles, again I have no idea why you'd blame Amazon in particular, but here especially, people simply are not replacing laptops in 2 years like they did 10+ years ago. It's a real "problem" for the PC industry in fact, because people are keeping their PCs around a lot longer than they used to. I've got a few laptops ranging from probably 4-6 years old, and lots of people have desktops quite a bit older than that. New computers just aren't any faster than old ones, they only consume a little less power.
Consumerism is something you can only really blame society in general for. And these days, with this crummy economy, I think it's probably less than it used to be: with rents so high nationwide, and salaries stagnant, and underemployment rampant, people aren't spending as much on trinkets and junk as they used to. Some things still are popular to spend on, like phones (but not computers), but overall I would imagine there's less "consumerism" right now than there was back in 1999 because we are not in a booming economy. When people have extra money to spend, they spend more; when things are tight, they don't.
As for valid (IMO) complaints about Amazon, here's my list:
1) they jerk their prices around a LOT. I have stuff in my "save for later" cart that keeps jumping up and down by huge factors (one pen in particular keeps jumping between $5-something and $9.99). Many things seem to start out at a low price, and then when I put them in my cart but don't buy them right away, they just keep going up and up and up. It really feels like a ploy to extract more money.
2) their prices are frequently not that low anymore. I always try to shop around for stuff, and will frequently (but not always) find better deals at smaller sellers.
3) a lot of stuff they sell is junk shipped from China, and it's not immediately obvious that it's being shipped from out of the country.
For a lot of small knick-knacks that I need (for instance, I needed a new windshield washer nozzle recently), I'm finding that Ebay is actually the best place to go, strangely enough. Independent online stores (even ones owned by companies selling on Ebay) usually cost about the same, maybe slightly less, but then have high shipping charges which isn't helpful if you're only buying one thing, and it's really easy to punch in a part number and find something on Ebay. You can find it on Amazon too, but it usually seems to be a much worse deal, though I'm not sure why. I wonder if Ebay has lower fees for large-volume sellers than Amazon. The main thing Amazon is really, really good for is the reviews. And even these are suspect these days because for certain classes of items, many of the reviews are shill reviews, or at least suspect, because someone was given the item at a reduced price in exchange for writing a review.