There are many people at various stages of musical development who hand out advice just about as frequently as doctors handing out lollipops to their patients after a visit. While there are some very knowledgeable and talented individuals out there from whom one can gain more knowledge and insight, there are also people out there who not only trip over their own shoelaces but trip others up along the way. The problem is how to identify them.
One thing that is evident though is that such individuals will tell others about some imagined shortcut they can take to speed up the learning/development process, which by the way almost never rings true. For example, when it comes to learning to play guitar solos some people will even go so far as to say that the focus should be on learning arpeggios and not scales. In reality, both chords and arpeggios (broken chords) are contained within scales so the idea that one doesn’t need to bother themselves with learning scales is a huge misnomer and bad advice in general.
In both my personal and professional opinion as one who provides guitar lessons, I don’t give a whole lot of weight to the credibility or competency of anyone who tries to tell someone that they can disregard a major piece of the musical puzzle and still end up becoming a proficient guitarist. There seems to be a kind of hurry up and cut to the chase mindset in a fair amount of aspiring players, which is indicative of a serious lack of patience which the learning process demands, because learning to do one, two, three or even four things really well is the building block to becoming proficient in any endeavour.
Learning to play a musical instrument is not something that happens instantaneously, and neither does any other activity. Being a great rhythm or lead player takes time, and becoming a balanced-well rounded player takes even longer, but the work it takes to get there produces untold rewards. Being a balanced-well rounded player can be taken to mean that one is either fluent in or can easily adapt to playing different styles of music, but what I am referring to in this case is the ability function as both an effective rhythm and lead guitarist, which serves to make one invaluable in a solo, duet or band situation.
To be clear one can choose to be strictly a rhythm player using open, barre and broken chords, never soloing at all and end up doing some pretty cool stuff on the guitar. A lot really depends upon the style and complexity of the music that one desires to play. My advice will always be that even if one plays little to no lead at all, and never intends on doing any soloing whatsoever that they still engage in a well-structured practice regimen, which includes the learning of scales. Many people will opt to just play chords (rhythm), all the while never realizing that there are the natural rise and fall patterns in music, which means that those chords are escalating and de-escalating (ascending & descending) in pitch.
So, what is the bottom line here? The bottom line is that every piece of the musical puzzle counts when it comes to learning to be a proficient guitarist.