I say you don't have sufficient experience not because I am high rank. I did not support my argument with my "high" rank. You basically just fabricated a random the high rank e-peen argument. In fact, what I said was extremely general and quite vague to be honest, but it does get to a point.
So what do I actually mean by "sufficient experience?" Well, I personally do not think one should have full rights to dispute something they do not have full understanding of. For instance, I should not be fully trustworthy in an argument of what should be allowed in osu!mania mapping, or of whether a big kat/don should be allowed to be placed at the end of a stream in Taiko (just to give a few in-game topics). I do not play osu!mania or Taiko at a level where I can say that I understand these things.
In the first example, I may have tried mapping o!m before, but I will not be able to play so-called "bad" mapping techniques and patterns and understand that they are bad, and thus I cannot say such patterns are bad or good without second-hand experience (from better players). In the second example, I cannot play taiko, so even if I believe that it shouldn't be allowed, I would not have a very valuable opinion because mechanically speaking I can't play the pattern either way, and therefore my opinion is not as highly rated as people who understand and play the game mode better.
Generally what happens is that, even if you don't realize it, you will often time be complaining about something and offering an alternative that serves your own needs more than the community's. You are asking to make the osu! mechanics slightly easier by adding this notification, because part of you thinks it will benefit the game, but also because part of you cannot play such patterns (and it annoys you). When you can play the such patterns perfectly fine, and you still think that it should be changed, then a more reliable argument can be formed in my opinion.
It's basically the same thing as some other dude in the o!m forums, who complained about how stupid it was you had to release at the correct times for sliders (in addition to hitting them at the right time), even though he has barely played. His opinion that it is a bad idea and that it should be changed cannot be valued very much because he cannot play o!m and he does not fully understand the slider mechanics of the game mode. Once he can play o!m legitimately and understands the uses and mechanics of sliders, then his argument would be more valid.
Now furthermore, I can give a similar argument as to o!m slider situation: that learning to read patterns in osu! adds an extra layer of difficulty to the game. And anyway, this extra layer of difficulty only comes into play on harder difficulties (i.e. insanes and extras), thus it does not make it more difficult for beginners to get into the game. At first it might be a little awkward, but once you can understand and read the patterns it becomes a lot more fun and satisfying. Basically, adding a notification is similar to having someone tell you that there is going to be a surprise birthday party for you. You will be happy that your friends are doing this for you, but at the same time, you lose the great excitement of experiencing the surprise. You can also apply to movie spoilers in an almost similar way, though you will probably be more disappointed in that case.
And maps like these are not as rare as you think, but everyone has been telling you that, so it's not really much use for me to talk about it again.