It is not only SK/EuroBonus, eg. Asiana Club credits 200% for F, 150% for A (discounted F) on Asiana flights.
For Lufthansa, Swiss, SQ or Thai F (doesn't matter F or A) only 150%.
You need to look through all the programs and compare. I guess the number of people which regular fly paid F and would mind about earning 150%, 200% or 300% of miles is rather limited. Most of them won't care at all. Just remembered my last flight on LH F BOS-FRA where the purser chatted with a lady which flies that route every other week in F and doesn't even have a FFP. No need, she said when the purser asked her why she doesn't sign up.