Here's the same issue again...every year.

The roster protection at 27 ensures team stability from year to year. With a good team, one still has to cut and/or trade veterans to keep roster spots for prospect development.
Cutting to a smaller number, would really make team development almost a moot point. One would have to dismantle the team and start over every year.
The process of team development takes 2-3 years, in my opinion, and if done well, can lead to a competitive team for several years. Subsequent drafts either add prospects to keep the team afloat (like the real Atlanta Braves with younger guys taking on roles as they are ready), or become trade bait to pick up a key player for a pennant run. This process of team development, scouting the drafts for those unknown prospect gems, and assembling a winning team based on one's deep knowledge of MLB and MLB players is the most fun part of the game.
If I had to dismantle my teams and start over each year, the whole game would lose alot of it's appeal. The perpetual leagues are the backbone of PB...to try to make them into virtual launch leagues would ruin the game.
The worst teams have the advantage of earlier rookie picks in each round of the rookie draft. I routinely get good prospects in the 3rd and 4th rounds of the rookie draft...and since my teams are usually winning, the picks are late round. The teams with earlier picks often make poor quality selections...and don't improve as much as they might. That's ok...the Tigers have that same problem too. Keeping the FA draft random gives a certain unkown to the draft process. If I trade for a FA pick, I never know if it will be early or late...which is a gamble which is fun to take.
So I am against any changes to the current draft process, or cutting to any lower number of roster spots after the rookie draft.
My $0.02 deposited.