You have not provided any tangible evidence to refute it. You simply don't like the idea.
What are the component chemicals of Novichok and what are their shelf life? You have not answered this and I doubt anyone could.
Russia not only has the means means, motive and opportunity but also has this mode of operating.
Only two contries have ever been known to make it. Russia and Iran.
Who is your alternative suspect and how did they optain the toxin?
What idea is that? It is simply a fanciful theory backed by nothing more than conjecture.
As you are keen to point out yourself, "What can be asserted without evidence can be dismissed without evidence".
The mixing of the component chemicals is the tricky and dangerous part and the theory that unnamed persons took some old Soviet stock to mix together 25+ years later has literally nothing to support it. Who, when, where? What lab did they mix them in 25+ years later? To call it a theory lends it a stature it doesn't deserve.
Your belief that the only two countries known to make it being Iran and Russia is just intellectually lazy, wrong and lacks any context.
Iran synthesised novichok under the supervision of the OPCW in 2016. Now if you were genuinely curious, and not just intent on blind jingoism, you may wonder why Iran did this. Things like this do not happen in a vacuum.
Prior to this novichoks were not listed as a prohibited chemical weapon by the OPCW because the consensus was that they were not viable and had never been successfully synthesised.
Wikileaks have released emails between US and UK OPCW delegations and State Dept. discussing how best to divert from discussing novichok and prevent it's listing by the OPCW. The reason other countries delegations were bringing up the subject was because of the revelations of Vils Mirzayanov , a Soviet scientist from the chemical weapons programme, who defected to the US where he still lives. In his book, still available, "State Secrets" Mirzanayov actually gives the formula for novichoks. The US and UK delegations made sure that the OPCW did not list novichoks and the email trail proves this. Read it below:
http://www.moonofalabama.org/2018/03/clinton-state-department-discouraged-novichok-discussion.html Do you think that perhaps the Iranians had got wind of US/UK shenanigans and probably the knowledge that the US/UK had successfully synthesised novichok? Would this explain Iran's working alongside the OPCW to produce it themselves and get it listed by the OPCW? Why did US/UK delegations seem keen to prevent novichok being listed?
Or do you think that the Iranian interest had nothing to do with the questions being raised by many delegations and they just produced novichok for no real reason?