When the first 5 and 10 euro coins were issued, casual collectors often stopped.
Do you think 1c , 2c ... 2E of one country and 1c and 2 c of second ? Or maybe the same coin by one country every year by 5 - 10 years ?

Casual collectors is every person on the street

It is not true collector .
France and Austria overdid it and others, like Ireland, are quite difficult to get.
I do not understood where is the difficult. No problem to find each of this coin .
The commemorative 2 euros made another wave of people who stopped collecting, even more because because there were also common issues.
Do you think 3 common issues to this day is a reason to stop collecting by someone ? Strange think.
New euro countries became one more hurdle to take, as some of them had small and faraway economies.
I do not understand the connection between faraway economies and collecting coins from , but "hurdle to take" is good. If all will be ease and cheap to take, collecting will not make a fun.
Those who included mint marks and mint master marks "need" more and more of the same.
? This year collector can add only one set to the collection : Slovenia - mint change. But because no mintmark will be used on new coins and on old coins , 2012 year can be a year without adding any euro set to the collection. Is this many ? If collector will have to add 2 sets next year , will it be many ? This is a little as I can say boring.
Even those who did none of the above were hit by chicanery exemplified by Belgium, where just about every year they managed to change something.
This is the best. It should never repeat in future and keeping all changed to this moment will be valuable if from 2011 to 2030 you will not see any change. Like SV , it will never come back and this set from 2005 is unique.
At some point, the euro issuers will kill the goose with the golden egg. Euro coin collecting has gone from easygoing to deciding what not to get, from checking change to shovelling out money, from fun to frustration. There's no need for euro coins to become static, like Switzerland or the US, but there's no need for these enormous emission programmes either. Could we have some middle of the road normalcy, please?
Wrong. You can collect everything , but you will not collect many ( no time, money, space ... ) . This is a core of collecting- good selecting your collecting interest .
You have to decide what you want. Many issuers of euro coins are the best in euro coins subject. You have many possibilities. Only you will decide which one you select. Can be something better ?
Do you need only 2E CC , no problem. Only 2E CC Proof , no problem. Both of them , no problem. Only all sets ? Or only some sets , no problem too. Silver or gold collector coin-like coins - you can.
.. but if someone wants to collect only 2E CC standard and exclude V/SM/M ... he will be casual collector in my opinion.
Tom