I don't visit NP's but once evey few years if lucky. For me anyway I could care less if I get a discount at NP's. I bought my SP when it was $10 or $20.
We mainly use it when camping at Forest Service type CG's. It gives us a 50% discount. I also take advantage of some CG's that offer a discount for being over 62 or higher. Why not? All this BS about I'm too good to need a discount is ridiculous. If they didn't want you to take a discount then they wouldn't offer it to you.
As far ass the Gov reducing the times for discounts, I have no problem with that either. Everything's more expensive every year so more revenue is needed for maintenance.
I look at it this way. Your work place offers gives you a bonus at the end of the year. You complain that it's too small. Fact is they don't have to give you one period.
Same with the SP. Be lucky you get what you get.