Seriously. What's the point in complaining?

First, I do not like Other M.
Second, your "observation" is most likely biased and do not reflect any actual real statistics for sure. Because I can tell you that I know very little people who likes Other M but on the contrary several ones who are actually looking forward for Metroid: Federation Force (including friends and my kids)

On a side note, this hate toward Metroid: FF is really reminding me of those people who "disliked" Diablo 3 when Blizzard presented for the first time because of the colors/art style behind not "dark" enough to be a "real Diablo" games :) This is really extremist and I see the same pattern with Metroid: FF; the gameplay is not even being challenged; the "kiddy" look seems to be the problem here for some Metroid fans more than anything else.

The disdain/skepticism for it is largely rooted in context, which I think is necessary for understanding things. For many Metroid fans, not only did Other M trash Samus' character, but it was also barely a Metroid game, swapping the exploration based gameplay for a very linear action title broken up by long cutscenes. Six years have passed since then, and we hadn't heard a word about Metroid until Fed Force. People have been getting pretty sick of waiting not only for another Metroid title with isolation and exploration as its focus, but also for a game to try and help erase the last memory of Samus' character.

Having the next game in the series be a title that addresses neither of these issues is the big problem. If this had been released in, say, 2006 or something, no one would have batted an eye. But the problem is is that people have been questioning whether Nintendo has any idea what they're doing with the Metroid series since 2010; arguably no Nintendo series has had its future more in limbo over the past six years. To release this as your next game in the series does absolutely nothing to provide confidence on that level.

First, I do not like Other M.
Second, your "observation" is most likely biased and do not reflect any actual real statistics for sure. Because I can tell you that I know very little people who likes Other M but on the contrary several ones who are actually looking forward for Metroid: Federation Force (including friends and my kids)

On a side note, this hate toward Metroid: FF is really reminding me of those people who "disliked" Diablo 3 when Blizzard presented for the first time because of the colors/art style behind not "dark" enough to be a "real Diablo" games :) This is really extremist and I see the same pattern with Metroid: FF; the gameplay is not even being challenged; the "kiddy" look seems to be the problem here for some Metroid fans more than anything else.