Why catalytic stoves are required to have lower emission limits?

It is best stated in the 1988 September issue, of one of the industry's leading magazines and I quote word for word from the article:

The article reads:
The EPA is on record stating catalytics represent the "best demonstrated technology" the industry has today. In other words, it's the federal agency's policy that combustors are the best solution to the wood smoke problem.
The EPA points to the following factors:
-More than 60 manufacturers use combustors in their stove designs.
-Catalytics deteriorate, but the EPA figures consumers can expect to squeeze more than 10,000 hours out of the combustor.
The deterioration of combustors is an improvement point, because the agency compared the lifetime performance of catalyst and non-catalyst units.
They note that catalytics burn cleaner than non-cats during a stove’s early years.
However, the emissions put out by a catalytic stove increases as the combustor ages. Both types of units burn about as clean, when averaged over the lifetime of the stoves, according to the EPA.
(end of article)

This is why the EPA's Phase I and Phase II emission limits, on wood burning stoves, are set the way they are.
However, catalytic stove technology has came a long way since this article was written.
Catalytic stove designs have changed since 1988. The catalytic combustor is now well protected from firebox flames in all catalytic stove models.

I would like to add this comment:
I have talked to consumers over the years, that had catalytic units that held up for 10 to 15 years and were still working on the day they called me.
Easy to see why FIRECAT combustors are offered to consumers with a 6 year prorated warranty from the date they buy a new catalytic stove.

A few more related comments:
1. FIRECAT catalytic combustors are made of high temperature, honeycomb ceramic and will take up to 2400 degrees F. before they reach, what I call a glazing point. Naturally, the stove will never reach this kind of operating temperature to destroy the combustor. They are durable and hold up well under proper operating methods.
Flame impingement and thermal shock, not normal operating methods, can be another story altogether. This will be addressed at a later date.

2. FIRECAT combustors are coated with noble metals that act as the catalyst. They never go away or wear out. Only ageing, abuse or improper operating of the stove will stop them from doing their job.

3. FIRECAT combustors can save the stove owner a lot of money over the years.
Consider fuel costs alone. (as much as 1 less cord out of every 3)
By burning low, they will save on fuel costs and best of all with no sacrifice of BTU output.
The FIRECAT combustor will produce temperatures that are at least twice that of the firebox. Therefore, they don't need high flames in the firebox to produce heat to keep warm.
Check out the catalytic stove's efficiency and do some comparing.