“You say ‘you want to get a rose’, not ‘you want that you can get a rose’.”
“I can get a rose” is different from “I want to get a rose”. The fact that “I can get a red rose” does not necessarily mean that “I” want it desperately. Is it for this reason that the “rose” statement that begins with “that” is incompatible with the expression “if for no other reason than …”?
“If for no other reason than that George Orwell wrote his essays in English, one ought to learn English.”
What do you think of this? In this sentence the reason is related to THE FACT THAT he wrote good essays in English.
It is not really a matter of being compatible or not but how smooth and natural it sounds, I think.
A sub-clause introduces a new layer and makes the sentence heavier than without it, so generally it is better to avoid it if you can.
For example, “In order to get a rose, you …” is better than “In order that you get a rose, you…”.
In most cases where the subject is shared between the main and sub-clause, the clause can be converted to an infinitive or gerund phrase.
(And the semantic difference between “I want to get…” and “I can get …” disappears when it is made into a sub-phrase, I think)
But of course it doesn’t mean that the sub-clause version is wrong - it’s just slightly redundant.
A google search returns about 580K hits for “if for no other reason” without “that” at the end, and 290K with it.
So we can say roughly that about half the times it is used without the “that” clause.
The LingQ forum used to have no trolls. If for no other reason than that, you should have posted comments on the forum and enjoyed reading other members’ replies.