People need to stop praising ME1

It's no good simply insisting black is white and accusing anyone disagreeing of being a casual, dude. There were less enemy types in ME1, the 'faction' system was far more primitive, and the bases and mines were copy-paste jobs regardless of world, opponent or quest. While it's fine if you honestly preferred that, trying to argue that they were actually better is just going off into fantasy land.

I've no idea what you're going on about when you mention the locations were 'well thought out' compared to MEA. The main quest areas were good but the rest of the game was a choice between one of a few enclosure layouts in a desert.

The weird thing is here is that you're actually focusing on the areas ME1 did badly. ME1's skill system was a lot more sensible and modular than MEA's, and the way combat powers are tied to the gun in question made far more sense then the way they were implemented in all further games in the series. But you don't talk about them, you just try to claim that the game with the fewest guns, enemies and level layouts somehow had the most variety, then make some silly assumptions about how many times anyone disagreeing with you must have played it.

To be fair it was their first time doing a cover shooting rpg. Most of the others had the d20 system.

Alright.  I find them to be about the same.  They both recycle the same handful of enemies and structures over and over.  I don't see hating one "far more" than the other though.  MEA just puts more meaningless land to traverse between them.

I don't know which game actually has less enemy variety, but when I played through MEA, it definitely felt like enemy variety was severely lacking.  However, part of that could simply be that I didn't enjoy the design or mechanics of most of the MEA enemies, unlike, say, ME3.

And I think that's part of the answer why ME1 got away with many of its flaws. It was the first time for a lot of things. ME1 development wasn't easy, as we can easily see by how different some of the early gameplay looked. It's only expected that a developer not might get it right the first time. We see it in other franchises as well. 

ME2 did a better job with enemies than Andromeda. 

Enemy variety is more than just the number of different enemies you have in the game. It's about how often you fight them, why you fight them, for how long, where, etc... 

ME2 had three different factions of mercs that largely did the same thing, a main opposition that you only fought three times in the game, and some wildlife and Geth layouts that were similar to ME1. While they improved upon ME1, you handled virtually every faction the same way as they were all basically guys with guns.

You had a few dogs and whatnot but nothing like ME3 introduced. MEA didn't really expand on ME3 all that much (the Kett in particular are pretty much unit-for-unit translations of the Reapers), but that isn't the argument being put forward.

Yes, but it never felt that way. 

Garrus loyalty mission is a superb mission in part because of this. You fight all the three mecenary groups in that mission. 90% of the enemies are "basically guys with guns", but it feels you're fighting very different groups. Moreoever, you know their leaders, and you end up fighting them. It gives a superb pace to the mission and an context for the fights that make them different from any other in other missions, even though you might be facing the same guys. 

ME3 is kinda king when it came to enemy variety. ME2 doesn't really come close. 

That's why I said enemy variety is more than just how many different enemies you have.

ME3 had the most variety, but think most of its missions weren't very well crafted. The Phantom, for example, which for me is the best deisgned enemy in the series, doesn't stand out in a single mission in ME3. That's because the correct use of squadmates make the encounters trivial. In MP when that doesn't happen the Phantoms are a joy to fight.

But back to the point. Having 10 different enemy types doesn't guarantee gameplay variety. They tend to help, but by themselves matter little. 

Look, I only fought like 4 enemies types in this game. And MEA is still more lazy copy paste in main mission or side missions. MEA is the most repetitive designed game I've ever played.

Also replay value is the best merit of a game's gameplay fun factor. With this in mind, no way will Mass Effect fans play Andromeda more then they've played ME1. Unpossible.