i see the ratings in the mangago as a social one. if you combine individual rates it's natural to be on top. and if i am going to rate it in a non-personal view, it'll be at the no. 1 as well. it's wide readability did it mostly since artwork and smut-romance-action balance can be contested.
sure, viewfinder is one of my all-time faves but for a personal opinion my rate is
1 yuutsu na asa
2 saezuru
3 viewfinder
4 hyakujitsu
5 ten count
Finder also has the most views and is the most popular - if you search for manga by those filters, them the star rating also drops - top five by popularity: Finder, Ten Count, Love Stage, Hidoku Shinaide and Caste Heaven, and by views: Finder, Hidoku Shinaide, Sekaiichi Hatsukoi, Katekyo and Haru wo Daite Ite. The star rating does not always reflect popularity - personally I only gave Katekyo 3 stars - but still it was a good manga. (An I gave Caste Heaven no stars - hated it ...)
The Finder series is one of my all-time favorite mangas, so my opinion is biased, but I think it’s so popular because it has a little bit for everyone. It has plenty of graphic sex scenes for people who just like reading yaoi for the sex; but it also has a plot, action, drama and the occasional comedic bit, for people who want more from their yaoi. In my opinion, it’s not shallow but it’s also not overly deep. Also, it’s been around way longer than Saezuru Tori wa Habatakanai, so it has more of an established fan base.
You think Saezuru Tori wa Habatakanai is better than the Finder series, that’s great, it’s your opinion and you’re entitled to think whatever you want. I agree that Saezuru Tori wa Habatakanai is better in terms of plot and characters. Saezuru Tori wa Habatakanai is also a much more impactful manga than the Finder series. Even though it has glowing ratings, in terms of views it’s much lower on the list. Also I think it’s not as readable as the Finder series, not saying it’s bad, I’m just saying it doesn’t appeal as much to the lowest common denominator.
So what's your point here, OP? You're astounded to find that lots of other people like something you don't consider worthy of such acclaim? Welcome to the concept that not every book is for every reader. Clearly, Finder meets the needs of a high number of readers. Gnashing your teeth over your fave not getting the same attention is pointless.
Personally, I agree that Saezuru is better written, but it's not as entertaining. And while its subversion of yaoi tropes is one of the things that makes it great, that very subversion sets it on the outer edges of the basic function of yaoi, where Finder hits it right in the bulls eye. That may not be what you're reading for, but again, not every book needs to meet your specific needs and tastes in order to be a good book.
I would also argue that for the careful reader, Finder does have depth beyond the tropes it embraces. It weaves complexities of plot with the subtle developments of a complex relationship just as well as Saezuru though perhaps without the gravitas. While Yashiro and Doumeki obviously run counter to the textbook definitions of uke and seme, Akihito and Asami both fit and expand those tropes, which is perhaps a harder feat to achieve.
So while Finder may be a sort of populist yaoi, it is first class populist yaoi and that is what places it at the top of those lists.
I'm not really complaing, just making an observation. As I said I also rated it 5 stars, but for me it's really suprising that story "hits right in the nail" of what entertains in yaoi for most people.
Also, all the other four on the rating list that I brought up are my favorites and I'm not really concerned for them not to get number 1 spot (maybe when they have as many votes as Viewfinder), that's why I was surprised with the number 1 spot, since my taste is very cliché. Or so I thought.
Just for curiosity, I looked for the ratings of the most popular yaoi series asd four of them stands out spetacularly:
1º - Finder series - with 87.7% of 5 stars
2º - Sekaiichi Hatsukoi - with 85.2% of 5 stars
3º - Junjou Romantica - with 83.6% of 5 stars
4º - Haru wo Daite Ita - with 83.5% of 5 stars
With that said, I just want to do a remark that I do not understand at all the obsession with the Finder series. I mean, I voted 5 stars also, but I do not consider it to be in my favorites. It is the series with the most count of votes, almost double form the other ones form this list, and all this time that I visit mangago (daily - from about one year) it is always in the list of most popular of the day! Every other one is missing on this list one day or another, not View Finder! Well... Saezuru Tori Wa Habatakanai is way better in my opinion. By the way, it has 81,9% of approval, wich makes it the 5th place together with Ten Count, but it's a tight spot, since other series are close form this rating, such as Katekyo!, for exemple, with 81,8% of 5 stars.