There have only been 8 offer sheets signed in the Cap era. Of these, only one was not matched (Penner). Six of the eight were signed in July, and one was the ROR holdout debacle that was offered in February. A late summer/early fall offer sheet in the salary cap era is a very rare thing. Not impossible, but its clearly not a move GMs look to do during their offseason. In fact it seems like its not a move GMs like in particular at any time. Signing an RFA to an offer sheet is only successful if you price them out of their current team's salary structure, meaning you are likely overpaying them at least up front. That has implications in a cap league, and further implications down the road when it comes time to offer them a UFA contract that will also be inflated because their RFA price, as their starting point, was inflated.
Also interesting to note that of the eight players who signed offer sheets in the cap era, seven of them are no longer with the team that either offered or matched. Now that could just be do to good old roster turnover, but you have to wonder if a player signing an offer sheet is a good tactic either. Are agents going to encourage it? Probably. But it clearly doesn't mean you are guaranteed to be changing teams and almost certainly damages the relationship between the player and the GM at least a little bit.
You can counter this stuff with whatever you want, but if you look at the teams in the league with the requisite cap space, draft picks, and expansion protection slots available to make this move, and then look long term to see if it may damage their salary structure down the road, the number of teams capable of doing this becomes very few. Add to that the rarity of the offer sheet in general, and specifically this time of year, and the small percent chance that it is not matched, and you have an scenario where it seems ridiculous to be devoting this much debate over. Especially when considering that most of the people posting here are fans of teams that have their own RFAs yet to sign, or don't have the requisite picks/cap space/expansion protection slots.
And as a final note regarding the Ducks salary situation. No one knows what the internal budget will be for this season or any season going forward. It is not a figure that is often discussed by management. But you better believe that with the expansion cash coming soon, our internal cap would be as high as necessary to keep our franchise cornerstone defenseman. Lindholm is not going anywhere. Get over it.