Of course, that's a given. Poems are written word, with the rhythm of words alone. Song lyrics however are only made to be heard, not read.Fire and Rain at least is ABAB in rhyme scheme. That said verses in particular don't need to rhyme at all (which is a no-rhyme rhyme scheme) Full rhyme, is perfectly fine too. I think where people take issue is where the words haven't been chosen creatively, and making the rhyme seems to be more important to the writer than meaning. Lyrics are a component of a song, not a stand-alone item. That does not mean that a reader will not ompose a melody in their head, or at least try and get a rhythm. Certainly some songs lend to that, others do not. There's room for all. None the less, predictable, unimaginitive rhyme comes over as "too much rhyme" in the exactly the sense of rhyme over substance, and often doesn't work out well when sung. Sure the melody might make the song, but from experience often doesn't. Those songs just become the many songs with great melody and poor lyrics. True, they can still be hits. Certainly using a strong rhyme does not guarrantee a great song, neither does using a no-rhyme rhyme scheme. There are great and poor songs of all kinds, all genres.
Rhyme is important, however, in that it can be both creative, subtle or blatant, laid back or in your face, but it works best when used consistantly through comparable sections. Some full-rhyme songs are certainly more suited to certain moods. A full rhyme AABB or ABAB can be altogether too bouncy for more sombre songs and the opposite is true for no-rhyme songs. Not that it will never work, more that it is perhaps not the best scheme to use for a specific purpose and emotion.
Critique is a discussion. Comments on lyrics or music in isolation should be given and taken completely under the proviso that what is being critiqued is not the complete work, only a component. Comments are just that. An observation of the lyrics or music in isolation. The writer(s) is(are) the only one(s) to have any idea of the overall feeling of the finished work, however those offering critique, can, based upon writing experience, gauge whether the rhyme scheme, meter, and language are suitable to the emotions they experience on reading (hearing their own melody in their head, suggested by the same aspects of the work). It's your work. You accept the comments or not, as long as you understand why the comment was made, which is the whole point in critique being a discussion, not simply an opinion.
In general I would say the critique sections, many offering critique are minimal in effort, and the time that they devote to any one work is pretty transient. The wise ones really delve and give each due thought and consideration, after all they benefit as much if not more offering the critique than they would when receiving critique. The point for them is to exercise all their songwriting tools as much as they can when examining works that they are not emotionally attached to. I think that is often forgotten.
As the one receiving critique, most can spot those who have given more time and spent more effort than others. The depth of comment goes beyond 5 lines at any rate. Anyone can filter the interesting observations from the less interesting, the more or less thought out. Often those giving critique who don't put in much effort tend to give more extreme comments at either end of the spectrum, either pointing out only positive (pulling their punches if a punch is given) observations, or the liberation of the internet fuels more negative comments given without sensitivity to the feelings of the writer. Understanding their motivation, their reasoning is vital to putting their comments in context and giving due consideration so that you as the writer understands why. If you can say you understand why they say "too much rhyme", if you have explored that why and you believe in that case it is not merited or accurate, if you have a satisfactory explanation to yourself, then it is as valid as the credence you place upon those opinions and any offered solutions.
One point, to perhaps help reduce such full rhyme comments.... why not state in your post that you are happy with the rhyme scheme and you would prefer to focus on.... whatever, during the critique? Or perhaps say, you want to keep the full rhyme? It is after all your work, and you are seeking to get ideas, feelings, observations and suggestions... there is absolutely nothing to stop you directing critique for you to get what you consider teh maximum benefit from that critique. It also saves a lot wasted effort all round, and perhaps a degree of frustration on your part.