When you write 'ghazal' or even a nazm, it's not just radeef & qafia [rhyming system], but 'beher', 'wazan', the meter too you need to be aware of.
The entire ghazal has to be in one particular 'beher' [among many] & all couplets in the ghazal will be in accordance with this pattern. For ages, 'faaylun, faaylaat' has confused young writers.
To some, it comes naturally. You remember 'dohas'--the laghu [1] & guru [2] or even in lyrics [movie songs], the 'dhun'. Classical masters, bards who never studied, knew it well, it came naturally to them. Others learn it.
Initially, it appears too tough & master poets tell you basics, correct the mistakes. If one knows the system, it's good. If you don't know, try to learn. In many languages, poetry is no longer dependent on prosody. But it is also true that this art is the reason Urdu couplets and ghazals have tremendous reach, quotability and are remembered.
Don't dissuade: Knowledge of Prosody is not for patronizing, rejecting
Everyone is free to write. And, knowledge of prosody must not be used to deter and dissuade anyone. As the 'ustaad-shagird' system has weakened in recent decades, unfortunately, some senior poets, don't help, rather their command over the subject becomes a ruse to reject others.
I remember, I was sitting with veteran poet, Kausar Siddiqui, when he was asked by a young boy about 'arooz'--prosody. He instantly took out a piece of paper and started explaining the system of 'beher'. There are ways to easily make you understand when a teacher is around. How the words are broken, where you can take liberty, how much is allowed, etc.
There are arguments in favour and against this system. Debate has been going on for decades.
But it is still believed that if you want to write literary ghazal or even a nazm, (except Nasri Nazm), there has to be meter. But apart from that, there is another aspect.
For example, a youngster has a superb potential, he has imagination. He writes a ghazal or nazm, the master poet says, 'it is kharij az bahar' or simply junk, this is patronizing. Rather than telling, correcting and asking him to keep writing and learning, he tries to impress him with his knowledge of a 'lesser known art'.
The youngster gets disheartened, reads lot of books, but is still not able to learn, even the names of the 'behers' are so tough, he gets disheartened. In case, he tries to read Dr Naresh, understands a bit, then may watch Bhatnagar Shadab sb's videos, but there is a greater chance that he may get overwhelmed.
However, if he decides that there is no need to learn this craft and he starts writing in Hindi, presenting the same compositions in devnagari, he is hailed as a poet. In Hindi poetry, there is no such issue. The 'chhand' was was shunned long ago.
Uniqueness of Urdu poetry: A tradition of centuries and focus on art, language
It's not that 'arooz' is something that should scare us. It's an asset. When it comes to Urdu poetry, it is the uniqueness. And, Urdu has an extremely tough system about judging poetry because of a long history, tradition, three hundred years of master poets who took inspiration from Bedil and Hafez etc.
Anyone who knows 'arooz' naturally feels that the youngster who doesn't know it, is just not 'mauzoo.n' for poetry, and that it's junk. This is also an extreme view. I remember Ustad-i-Shahar Ishrat Qadri sahab in Bhopal, would instantly tell youngsters--go write prose.
'Aap ke bas ka nahi, aap rahne dijiye', he would say. He felt there were too many poets and there was need to focus more on prose. Then, you see those who know arooz, try to patronize, else dissuade others while on other hand give 'crash course' to son or preferred 'shagird', telling them the ways how to ensure that their ghazals follow rules, but reject others.
You must not patronize, decide or control what others write
Most basic thing in life is that, one must try to learn and if someone asks you something, share your knowledge, help them out. Lekin aap izhaar par 'qaid' bhi nahi laga sakte. If someone writes, he-she is satisfied, adhering to meter or not, it's fine.
They seek your help, you should give them the necessary tips. Every ghazal or nazm may not be literary as per your standards. But everyone has the freedom to express themselves. You can't hold others at gunpoint--write in meter or I'll not consider you a poet unless you prove yourself in this format.
If someone is writing, it's their choice. 'Paband shayri' ya 'azad', whatever they do, it's their choice. Don't give gyan, unless asked. And if asked, don't discourage but make person realise what he can do, best. Not 'Gyan ka Ghamand' or becoming a 'pir tasma-pa' unknowingly.
Similarly, if someone ready to provide you tips, you must be thankful and treat them respectfully. Lot of Hindi knowing youth are now learning arooz, practicing daily on FB. This is a topic that needs our attention, discussion and it may go on a bit longer.
Post-Script:
Not just ghazal, either it's Azad Nazm or Nazm-i-Muarra, all genres in Urdu poetry have 'beher'. The sole exception is 'Nasri Nazm' which many accomplished Urdu poets still feel is 'prose'--that is scattering sentences [prose] to turn it into a 'Nazm'. Many purists even believed that Nasri Nazm of only those people are worth consideration who can write ghazals, nazm in meter. However, there is a change in opinion now.