I totally disagree...but to be fair, I don't like "harems" for exactly the reason I'm going to speak of. Having an "obvious choice" isn't a bad thing--not when it's the actual best girl. I don't mean "best girl" by the word of one person with one taste or another, I mean the objectively best girl: the one who is, evaluated in her entirety, the most reasonably and logically appealing of all the choices. For years, there have been countless instances of such a girl taking the loser's march because--according to popular modern sentiment--all tastes are equally valid, all preferences are good, and all sums of feminine being are "beautiful". All, that is, except for those sums that are objectively appealing and have proven themselves to be so either through traditional precedent and/or sheer logic; if authors were pen their romances favoring objective beauty, such girls who embody those objectively beautiful sums--ideal beauties--would never lose to anyone. Some examples: the 100:0 tsun/dere would never win, because no one normal wants a battleaxe except for masochists; the androgynous, flat-chested shorthair would never win because no one except those conditioned to would reject a girl of full feminine development in favor of one who could pass as male; and the girl who appears to be or is of a single-digit age would never win in a story not meant to pander to pedophiles.
Because it's now "wrong" to declare any opinions invalid, all such tastes/fetishes must be at least treated as equally valid. Consequently, any embodiments of beauty that would absolutely crush the aforementioned by comparison alone must at least be given lesser portrayal at best. It's an awful convention, one that has not only strangled many romances (To Love-ru is one infamous example--particularly the first manga's ending), but has hamstrung others that have no business being concerning themselves with romantic compeition--like Mone-san no Majimesugiru Tsukiaikata. That particular story has a VERY obvious best girl...because it was meant to be a romance between one guy and one girl. Around ten chapters in, the author jerked the story over into harem territory and it suffered until the happy ending for the MC and FMC--the destination it was headed to from the start, but had to take unnecessary, major detours for; and all of that happened because every person with a taste/fetish has to be validated in this day and age.