Not to invalidate your post, but I'd have to disagree with you there.
It's not that I hate multiple solutions to one problem, it's that I hate how nothing feels planned. For example, that "leap of faith" in Gate stage 2? If that was supposed to be a wall meant to obstruct players that don't have some sort of necessary power up, that's fine. What's not fine is throwing it at the player in part 2 of the stage, especially after having to deal with the [parasitic bomb] storm that is Hi-Max and his stage. Because of the devs negligence or lack of sympathy, now you have to replay the whole part 1: if you struggled with it the first time, have fun struggling through it again. Most of the time, this issue isn't apparent, but quite often players find themselves in the situation when they picked Shadow Armor, but not Speedster/Hyper Dash/etc.
And about the element of progressively becoming stronger? The majority of X6, as least how I played it (which works, btw), is spent tanking enemies and obstacles because of how impossibly hard it is to avoid everything. In my head, I'm not thinking "so-and-so is charging at me from this direction, so I should dodge it like this". Instead, I'm thinking "okay, to advance, I have to kill this guy, so I'm just gonna focus all my crap on him and not pay attention to anything else". Instead of the difficulty placed on the reactions of a player, instead the difficulty is all in planning ahead. Personally, that is not how I want to play a Mega Man game.
For example, in X2 I might attempt to make a no power up run. It's hard as hell, but at least when I make a mistake, I know that it was my fault most of the time and there is indeed ways to dodge so-and-so. But X6? Unless I was a masochist, how can I blame myself when I can't even trust that the devs know what they're doing?
On the flip side of the coin, like what Sir Cromington said, that is also what makes X6 fun in its own, unique way, in that it's so horridly planned that players have fun attempting to survive the [parasitic bomb] storm. In that sense, I enjoy X6, but personally, I don't want future Mega Man games to be like that.