First of all- I do respect everyone's opinion.
It takes 24 to make a League, and we all have a stake and a voice in how the League is played.
I see where you're coming from & I have thought a lot about the Keeper Cap. My main reason for a 3 Keeper Cap is still for parity & viability of keeping the League going. In a perfect world if we had 24 owners committed to playing all 5 seasons, unlimited Keepers would work, but that's just not realistic. Even with 20 owners staying on and 4 new owners coming on board every season, hypothetically if everyone Keeps 3 fliers from the current era going into the next era, the top 60 eligible players will already taken before those 4 new owners have a crack at anyone. Some teams will only keep 1 or 2 guys, or none at all if they're gunning for a particular new draftee, so probalby more like 40-50 players will be off the boards come each new Season's draft. I just don't want to get in a situation where we can't get any new owners because too many guys are already off the boards and the League is less attractive to them than if they had some really good high talent options to draft from.
Also, at a $140 Mil Cap, how many fliers that won't produce much at all in the current season do you really want potentially hurting/limiting your current roster to hold over to the next season? Sure some players will have peak seasons in both eras, but you have to think about the net negative of drafting too many players for the future if it'll hinder your chances to be competitive in the current season. Ultimately, the overriding factor I think to limit Keepers to 3 is the overall parity of the League and viability of still attracting new owners from season to season. Still plenty of strategy on which 3 players you target to draft as Keepers for the next era, who pulls the trigger on them first and when you draft them. If you draft more than 3 studs for the next season, heck- make a trade with someone for a current player, or for a future Draft pick. I'll leave it open for discussion, but I've really given it a lot of thought and think 3 Keepers is the best way to ensure some parity and draw for new owners, yet still make the Draft & Keep factor a fun and competitive aspect.