Actually people would say “Avira dEretz Yisroel Machkim” (I would know better if I’d be living there!)
But to get to the question (and fake being sincere for a change)
Yes, the OP has a real valid concern and message. I, too, know of some who went there supposedly to “shteig” and ended up.. (or should I say down).
Eretz Yisroel is the land of Am Yisroel, kedusha, inherent kedushas ha’aretz, the land chosen by HaShem to suit the needs of His people. A sincere individual, looking for shleimus and kedusha will have an easier time there. There’s a reason why all our greats had a special attraction to that land, besides for the mitzvhos connected with being and living there. Read up on Ohr haChaim – how he describes Eretz Yisroel time and again, over and over… other seforim, full with wild enthusiastic praise of chibas ha’aretz.
And yet the “opposite side”, the yetzer hara, has not thrown in his towel yet. Ze leumas ze, he works overtime, especially in situations and circumstances of potential for great “Aliya”, he does his work, cunningly… (the game’s not over yet). So b’davka in such a setting of a potential of endless aliya in Ruchnius, Torah, Yiras Shomaim, Middos, you’ll find such a powerful force pulling to the opposite!
Now, let’s take a more down-to-earth look. You send your darling bachur off to a faraway place, he knows your not gonna peek in on him tomorrow… with a bunch of his friends.. They all chip in for a “dira”… Then some more “friends” move in… Sure.. Ameich Kulom Tzaddikim… they’re all tzaddikim (’cause all it takes is ONE rotten apple), all seeking the same Aliya. Sure. Ma yaaseh haben shelo yechta… everything’s pulling him to the wrong side.. teen feelings of freedom.. “friends”.. unsupervised boarding..
Again, everything has to be weighed and all sides and circumstances considered… still, there’s nothing better than a closely supervised Yeshiva setting – 24/7. A bachur at this stage must FEEL he is accountable for each action, each minute..