I don't think it's a conspiracy theory that conspiracy theories have become diluted. I think it's an unfortunate and unintended side-effect of the conspiracy theorist mentality.
Once you have convinced yourself that one conspiracy theory must be trust you make the logical mistake of giving the rest more credence than you would if you didn't believe in one already.

Let's use 9/11 as an example.
If someone believes that 9/11 was a false flag attack they must then believe that the US Government will:

- Lie to them
- Kill them to further their own agenda
- Have the organisational skills to convincingly pull off that false flag attack.

I make no judgments here about the veracity of those claims, but each and every 9/11 false flag believer must believe those things.

Once you have accepted those things as true you don't need evidence to convince you that:

- The US Government would also infect GMO's for population control
- Spray harmful chemicals out of the backs of airplanes
- Invade your home and take your family away from you to be put into FEMA camps.

The burden of proof for each of those conspiracy theories drops significantly once someone believes that 9/11 was a false flag attack. You don't need to be convinced again that the Government will lie to you about what is in GMO's. You don't need to be convinced again that the Government would spray harmful chemicals onto your town to further their agenda. You don't need to be convinced again that the Government would come into your home and kill you for dissenting.

That is, I think, the fundamental flaw with all conspiracy theories and conspiracy theorists. Each new theory lowers the burden of proof for the next one, and the conspiracy theorists standards for proof are lowered with each new theory that they believe. Eventually they begin believing things based on no evidence at all and it only takes one authority figure like Alex Jones to suggest it to them.

So conspiracy theories are fine so long as people don't bias themselves against one party involved because of other conspiracy theories.