I understand why, but here's the thing. "Querer" can be "to love" AND "to want." In most cases, you will use it as "to want" (while it may be true, in a restaurant you would say you want pizza, not that you love it, even though the word is the same). The context largely determines meaning, in this case, it's "I want water" not "I love water," not that DL always has the best examples, but it would be strange even for DL to say it loves water :D The context determines it :) Of course, sometimes it's more ambiguous: "te quiero": you love me or you want me or both? Hopefully this clarifies it :)
when you talk about thing, ''Quere'' means that you want something to be yours or you want to get something. but when you talk about people, ''Querer'' is used when you apreciate someone in a cute/sweet way. but if you strongly love someone like your mom, your dad, your wife/husband(be in love), etc.. you use the verb ''amar''
hope it helped
In Spanish because we conjugate verbs for each speaker, we don't always need the personal pronoun in the front: while in English you can't differ between "I want" and "You want" without "I" or "You," in Spanish you can easily do so: "quiero" "quieres." Which is why in Spanish the personal pronoun is more often than not omitted. If you listen to people speaking Spanish, most won't use them, and they are often used as a means to add emphasis or clarity, rather as a necessity as in English. In short: because of the conjugation, no, because it's already clear who's speaking. Hope this makes sense, and good question :)