I don't follow.
First of all, neither was over the MLE, and Miller was not a max MLE.
First, Miller was over the MLE, and Matthews was a full MLE that was front-loaded with the signing bonus (toxic).
Secondly, Matthews was (and perhaps may remain) a bench player for the Blazers. That puts him between 6-10.
Secondly, if you think that Matthews was brought in to be a "solid 6-10 role player" and not "starter when Roy's wheels fall off", we're just going to have to disagree.
Thirdly, why would we try to get a lesser player as a free agent if we can add a player like those two? Good players can be role players too.
I'm not saying don't go after free agents. I'm saying that POR gets the grand total of the MLE+BAE(every other year) to spend every year on fixing the rotation of 6-10. The vet min is available for 11-15 guys (what Juwan Howard was supposed to be). I'm just saying that you
might get one impact player for a full MLE, or you might not. You might get a couple of 8-11 guys if you split the MLE. But you're not generally getting a vital piece via MLE Free Agency.
Fourthly, that was just the last two summers. If you look farther back, guys like Joel Przbilla and Steve Blake (twice) and Juan Dixon were free agent acquisitions. I'm sure there are more I'm not thinking of.
Juan Dixon is an example of that 8-11 guy that you can get via the splitting the MLE, and so was Blake.
It is, under the current CBA at least, pretty easy to get rotation players if you are willing to sign the check. And the Blazers have been willing to do it.
And your examples have been Joel when washed-up (when he was healthy he was higher than MLE) Juan Dixon, Steve Blake, (I'll add Fred Jones and Ime Udoka), Travis Outlaw, Martell Webster, and I'm sure I'm missing someone. Blake is the only rotation player still in the league on a "better than horrible" team. Portland can only sign the same amount as every other team in the league, which means they're at a horrible disadvantage (Wes excluded). Did Hedo accept our check? Lee? Millsap? Juwan last year?
Bottom Line: If you have success in the draft, it allows you to keep taking risks. If you don't have success for a couple drafts in a row, you need "floor" players. POR needs to use the draft, b/c they're at a disadvantage in FA, and can only offer the same $ as everyone else.