In a previous post (here), I began to deal with some parameters of the mitzvah of yishuv Eretz Yisrael, focusing on the element of protecting the land. There are several indications that the notion of yishuv Eretz Yisrael means that there is a value to increasing the quality of life in Eretz Yisrael and not ensuring that Jews live in it.
The first source is from the Gemara in Tamid 29b.
תלמוד בבלי מסכת תמיד דף כט עמוד ב
החלו מעלין בגזירין לסדר את המערכה [וכו’] חוץ משל זית ומשל גפן [וכו’]. הני מ”ט? רב פפא אמר: משום דקטרי, רב אחא בר יעקב אמר: משום ישוב דארץ ישראל.
The Gemara rules that grape and olive trees should not be used for the mizbeach. The Rosh writes that, as the mizbeach needs a lot of wood, if we used these trees there would be not olive or grape trees left (and therefore no wine or oil). The Mefaresh adds that then the land would be charev. This may mean that people will move away, though he could simply mean, as is the simple understanding of the Rosh, that destroying the quality of life in Israel is problematic. Artscroll (note 20) thinks the focus of both is that when the quality of life goes down, people will move out, implying that yishuv Eretz Yisrael is narrowly defined as having people live in the land. I think that at least the Rosh and perhaps the Mefaresh as well are actually suggesting that yishuv Eretz Yisrael indicates a value for improving and maintaining quality of life in Israel. In the Meyuchas L’Raavad it seems this way as well – simply saying the problem is that we don’t want to destroy these valuable trees. Note that the Gemara in Bava Batra 90balso bans exporting oil, wine, and fine flower from Israel because they are chayei nefesh. If this means that people will die without these, or leave the country because they are basic, then perhaps this entire discussion is only about living in the land. However, it sounds like the discussion here is broader. The exact nature of the prohibition in Bava Batra is complicated.
We saw a similar ambiguity in the dispute between Rashi and the Sefat Emet as to why in Israel one puts up a mezuzah immediately. The Gemara explains this based on yishuv Eretz Yisrael. Rashi explained that because one will not take down the mezuzah, he will be reticent to move away, and if he does, it will be easy to find new renters. This indicates a focus on yishuv Eretz Yisrael meaning primarily living in the land. The Sefat Emet argues that as mezuzot provide protection, there is a value in keeping Israel safe, which seems to focus on the quality of life as being part of the mitzvah (though it could be that you need Israel to be safe to ensure that people live there). The other position that is often suggested, that in Israel your house always significant and permanent doesn’t shed too much light on this issue.
The Gemara in Bava Kama 79b forbids raising behemoth dakkot like goats in Israel. There is a dispute as to whether the primary issue is that these animals tend to graze in other people’s property and there is a concern of theft, or that they simply destroy fields because of how they eat and we don’t want to destroy the Land of Israel. Rashi takes the latter position, here focusing on the quality of life, though it could be that quality of life here would force people to leave the country. [Whether this prohibition applies today is a major dispute in poskim.]
The Mishna (see Erachin 33b and Gemara ibid) prohibits a planted field into an open asthetic one and vice versa, as well as prohibiting turning the designated parts of cities for dwelling into open fields and vice versa. There is a dispute in the Mishna if this applies to all cities or only the cities of the Leviim. At any rate, Rashi there writes the minimizing the number of fields that plant produce harms the goal of yishuv Eretz Yisrael, ands seems to say that same thing about removing the aesthetic parts of the city – making the city less naeh is also problematic. [Again, the paramters of what cites this applies to biblically, rabbincally, etc, is a discussion in the Gemara, Rishonim, and Achronim.]
In the Enclopedia Talmudit on the section Eretz Yisrael it lists many other obligations and dispensations that emerge from this principle that may indicate that there is a Halachic value to improving quality of life in Eretz Yisrael.
As a final note, there is a more general question as to the connection between quality of life for a community and the category of pikuach nefesh that may weigh in on this discussion. There are some who believe, based on a possible read of a Gemara in Nedarim 80b-81a, that the quality of life of a community is equivalent to pikuach nefesh. For example, see Rabbi Tendler’s article in Kavod HaRav (Beis Yitzchak 16) [as well as his general article on quality of life in Halacha in Beis Yitzchak 25]. If this is the case, and there is a value to the Jewish people living in Israel, one would understand why there would a Halachic value to improving the quality of life in the Land of Israel.