I didn't say they were less important, but they're one section of a greater whole. The fate of Doncaster, Ealing Trailfinders, London Scottish and so on need to be balanced against England's fate, Leicester and Northampton's fate, the fate of all the wee clubs scattered against South East London and North Kent who'll never, ever be able to make it to the top leagues and so on.
Semi-pro wages - you get them a long way down the league in clubs that have no hope of the big time (or for whom big time is London 1); you get them in Ireland, where club rugby will always automatically be the second smallest show in town; I presume you still get them in Wales; and you will continue to get them in the Championship and NS and NN too.
Highly competitive grass roots - I don't call a semi-pro organisation like Doncaster grass-roots personally, but in any case, why are players going to be less competitive? Are clubs going to stop working hard to reach the Championship? Look at Jersey, they've put a lot of back into reaching that level despite it being very clear they're not going further than that anytime soon. There is already a very sizable barrier between Championship and Premiership unless you have Premiership level infrastructure, you still have clubs working very hard to get there.
This country's national team - The likelihood is more stability allows for our rugby clubs to be better businesses. That should in turn allow for better facilities and squads. Which in turn, along with no risk of relegation, should result in better rugby and better player production. That should result in a better international team.
Player pathway - The majority of elite players in this country are picked up playing for small town clubs with no realistic Premiership ambition and play all their rugby bar a loan season or two at one of the top 14 clubs as is. The Championship stumbling would be a loss, but it is a) not certain b) has to be weighed against the advantages we'd get from ringfencing c) probably temporary.
